Faculty Profiles - SATSUMA, Atsushi

Papers - SATSUMA, Atsushi

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Atom-to-nm Scale Engineering of PtCo Alloy Catalysts over Supported Co Nanoparticles for Advanced Toluene Hydrogenation Efficiency in Hydrogen Storage Applications Reviewed Open Access

Oda A., Ogawa N., Yamamoto Y., Sawabe K., Satsuma A.

ACS Catalysis Vol. 15 ( 4 ) page： 3191 - 3202 2025.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Catalysis

Hydrogen storage and transportation are pivotal for a hydrogen- and carbon-neutral society, yet current approaches face considerable limitations in efficiency and cost, which are typically related to catalyst design. Alloying a trace amount of Pt on supported Co nanoparticles has emerged as an innovative catalyst design that leads to a substantial reduction of the amount of precious metal used in the catalytic hydrogenation of toluene (TOL) to methylcyclohexane (MCH), which is an important aspect of hydrogen storage and transportation. However, because of the difficulty in controlling the surface structure of PtCo alloy catalysts, the structure that maximizes the synergistic interaction between the Pt and Co sites has not yet been identified. In this study, we explore the structure-function relationship in TOL hydrogenation over PtCo alloy catalysts by designing three distinct structures: PtCo single-atom alloys, PtCo alloy nanoislands on Co nanoparticles, and PtCo alloy nanoparticles on a support, i.e., monoclinic-phase ZrO2 (m-ZrO2). In the catalyst designs, m-ZrO2 was employed as a support to control the Co nanoparticle diameter to 5-7 nm, maximizing the fraction of Co plane sites required for efficient TOL fixation/hydrogenation and enhancing the synergy with Pt site-derived functionality. The highest turnover frequency (TOF) had the following magnitude relationship: PtCo single-atom alloy > PtCo alloy nanoislands on Co nanoparticles > PtCo alloy nanoparticles on m-ZrO2. Remarkably, the PtCo single-atom alloy enhanced Pt utilization efficiency by up to 51-fold over supported Pt nanoparticle catalysts, resulting in record activity in the literature. Based on the kinetic experiments coupled with in-depth structural analyses using the series of well-defined PtCo alloy catalysts, it was clarified that the high activity is attributed to (1) optimal competitive adsorption of TOL and H2 created by Pt single atoms-containing Co ensemble sites and (2) large fraction of such sites. Stability tests coupled with microscopy confirmed that PtCo single-atom alloy catalysis remained stable for at least 24 h, indicating that the supported Co nanoparticles also play a crucial role in preventing Pt aggregation. Our findings underscore the importance of optimal atom-to-nm scale design of PtCo alloy catalyst for achieving ultrafast TOL hydrogenation even with extremely low Pt usage, offering an innovative approach for saving precious metal in hydrogen storage and transportation.

DOI： 10.1021/acscatal.4c07206

Open Access

Scopus

Encapsulated Platinum-Tin Nanoparticles in Silicalite-1 Zeolite for Methylcyclohexane Dehydrogenation Reviewed

Shi W., Oda A., Yamamoto Y., Harada S., Ohtsu T., Sawabe K., Satsuma A.

ACS Sustainable Chemistry and Engineering 2025

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Sustainable Chemistry and Engineering

Catalytic dehydrogenation of methylcyclohexane (MCH) is of great importance for hydrogen storage and transportation, but currently used Pt-based nanoparticle catalysts still suffer from insufficient activity, low selectivity, and short-term stability. In this study, we encapsulated Pt-Sn nanoparticles into the silicalite-1 (S-1) matrix and incorporated Sn into the zeolite framework through one-pot hydrothermal synthesis to overcome the above problems. These Pt-Sn bimetallic catalysts were designed for the first time with a high Sn content (2.8-3.9 wt %, Sn/Pt ratio = 6-8) in zeolite mother gel for MCH dehydrogenation. The introduction of Sn significantly improved the activity and durability of Pt@S-1. Especially, the PtSn@S-1 (Sn/Pt ratio = 6) catalyst showed high MCH conversion (>80% for 2 h) and toluene (TOL) selectivity (∼100%) without cofeeding H2. Even after a long-term stability test for 33 h under a weight hourly space velocity (WHSV) of 120,000 mL/g/h, no obvious deactivation was observed, and this catalyst retained a superior H2 evolution rate normalized with a surface Pt content of 1343 mmolH2/gPt/min. The structure-catalytic property relationship of PtSn@S-1 catalysts was systematically studied. Upon Sn introduction, PtOx species on Pt@S-1 were transformed into the PtSn alloy. With the further increase of the Sn/Pt ratio from 1 to 6, Sn was gradually incorporated into the zeolite framework, and this PtSn alloy evolved into a core-shell structure with a Pt core and a Sn shell. Despite the reduced proportion of surface Pt, these unique structures enabled the modification of the Pt local structure, promoted TOL desorption, and enhanced the stability of Pt-Sn nanoparticles, therefore achieving high activity, selectivity, and durability for MCH dehydrogenation.

DOI： 10.1021/acssuschemeng.4c09762

Scopus

Reversible Multi-Complexation of CO<inf>2</inf> to Alkaline Earth Metal Ion-Pair at 400 ppm and 298 K Reviewed

Oda A., Sawabe K., Satsuma A.

Angewandte Chemie - International Edition Vol. 63 ( 51 ) 2024.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Angewandte Chemie - International Edition

The efficient capture of low-pressure CO2 remains a significant challenge due to the lack of established multi-complexation of CO2 to active sites in microporous materials. In this study, we introduce a novel concept of reversible multi-complexation of CO2 to alkaline earth metal (AEM) ion pairs, utilizing a host site in ferrierite-type zeolite (FER). This unique site constrains two AEM ions in proximity, thereby enhancing and isotopically spreading their electrostatic potentials within the zeolite cavity. This electrostatic potential-engineered micropore can trap up to four CO2 molecules, forming M2+−(CO2)n−M2+ (n=0–4, M=Ca, Sr, Ba) complexes, where each CO2 molecule is stabilized by interactions between terminal oxygen (Ot) in CO2 and the AEM ions. Notably, the Ba2+ pair site exhibits higher thermodynamic stability for multiple adsorptions due to the optimal binding mode of Ba2+−Ot−Ba2+. Through high-accuracy energy calculations, we have established the relationship among structure, CO2 uptake, and operating temperature/pressure, demonstrating that the Ba2+ pair site can capture four CO2 molecules even at concentrations as low as 400 ppm and at 298 K. Three of the four molecules of CO2 trapped were removable at room temperature and under vacuum. The findings in the present study provide a new direction for developing efficient CO2 adsorbents.

DOI： 10.1002/anie.202411969

Scopus

Rutile TiO<inf>2</inf>-Supported Pt Nanoparticle Catalysts for the Low-Temperature Oxidation of Ethane to Ethanol Reviewed

Oda A., Kimura Y., Ichino K., Yamamoto Y., Kumagai J., Lee G., Sawabe K., Satsuma A.

Journal of the American Chemical Society Vol. 146 ( 29 ) page： 20122 - 20132 2024.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of the American Chemical Society

Structure-function relationships of supported metal nanoparticle catalysts in the CO-assisted oxidation of ethane to ethanol were investigated. A rutile TiO2-supported Pt nanoparticle catalyst exhibited the highest ethanol production rate and selectivity. During the reaction, sequential changes in the geometric/electronic states and the particle size of the Pt nanoparticles were observed. The comparison of the catalytic performances of model catalysts with controlled metal-support interactions revealed that Pt0 nanoparticles of 2-3 nm with a high fraction of the surface Ptδ+ species are highly active for the oxidation of ethane to ethanol. The coadded CO plays a pivotal role not only in tuning the oxidation state of the surface Pt but also in producing H2O2, which is the true oxidant for the reaction. The supported Pt nanoparticle uses in situ-generated H2O2 to activate ethane, where the C2H5OOH intermediate is formed through a nonradical mechanism and subsequently converted to C2H5OH. This reaction occurs even at 50 °C with an apparent activation energy of 32 kJ mol-1. The present study sheds light on the usefulness of surface-engineered Pt nanoparticles for the low-temperature oxidation of ethane to ethanol.

DOI： 10.1021/jacs.4c04381

Scopus

Pt single atom alloyed sub-1 nm thick Fe overlayer on supported Cu nanoparticles for methylcyclohexane dehydrogenation Reviewed Open Access

Oda A., Ichihashi K., Yamamoto Y., Ohtsu T., Shi W., Sawabe K., Satsuma A.

Journal of Materials Chemistry A Vol. 12 ( 34 ) page： 22655 - 22667 2024.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Chemistry A

There is an urgent need for the development of a precious metal-conserving catalyst having high activity, selectivity, and durability for methylcyclohexane (MCH) dehydrogenation, a significant aspect of hydrogen storage and transportation. A Pt-single atom alloyed Fe catalyst with sub-1 nm size is a good candidate for this purpose because of meeting site requirements for enhancement of activity, durability, selectivity, and utilization efficiency of Pt. However, this design is challenging due to the high surface energy of Fe. In this study, to break the limitation of catalyst design, we used a combination of two phenomena spontaneously taking place at the solid surface, i.e., (1) Fe dispersion on Cu, and (2) substitution of metallic Fe atoms with Pt cations. Here, we report a Pt single-atom alloyed sub-1 nm thick Fe overlayer on Cu nanoparticles. The Fe overlayer serves as the host metal to restrict Pt single atoms at the surface and provides an optimal coordination environment for MCH dehydrogenation. Furthermore, the sub-1 nm thick Fe overlayer features low crystallinity and superior decoking properties, which imparts product/coke poisoning resistance to the Pt single atom site, resulting in enhancements of both durability and activity. The H2-evolution rate per Pt mass was at least 133 times higher than that of state-of-the-art catalysts: Pt-based intermetallic compounds. This research demonstrates the significance of a single-atom-alloying approach with unique nanostructures specifically formed at the solid surface for the development of more efficient sustainable catalytic transformation processes.

DOI： 10.1039/d4ta03453h

Open Access

Scopus

Unveiling Static and Dynamic Structures of Pd Clusters Influenced by Al<inf>2</inf>O<inf>3</inf> Surfaces: DFT and AIMD Studies Reviewed

Murata K., Oda A., Satsuma A., Sawabe K.

Journal of Physical Chemistry C Vol. 127 ( 41 ) page： 20267 - 20275 2023.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Physical Chemistry C

Metal nanoparticles (MNPs) supported on oxides are used in various catalytic reactions, such as petrochemical processes and exhaust gas purification. Metal-support interactions (MSIs) between MNPs and oxides affect the morphology and thermal stability of the MNPs, which are known to be related to the catalytic activity of the MNPs. However, the effect of MSIs is still a matter of debate. We conducted density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) to investigate the geometric structure and migration behavior of Pd clusters on various Al2O3 surfaces. The MSIs of the Pd clusters with different Al2O3 surfaces resulted in different morphologies of the clusters. The shape of Pd clusters on α-Al2O3(0001) were deformed to oblate and on γ-Al2O3(110) to prolate. On the other hand, the shape of Pd clusters on γ-Al2O3(100) did not change from that in a vacuum. The migration rate of Pd clusters was also affected by the MSI, which was higher on γ-Al2O3(110) than on α-Al2O3(0001) and γ-Al2O3(100). To evaluate the interactions between Pd clusters and Al2O3 surfaces, we calculated the interaction energies for Pd clusters with various sizes on Al2O3 surfaces. The interaction energy of Pd/Al2O3 systems depended on the coordination number (CN, number of bonds per Pd atom) of Pd-Al and Pd-O. Despite the smaller atomic density of Al and O of the γ-Al2O3(110) surface than that of α-Al2O3(0001) and γ-Al2O3(100) surfaces, the number of bonds formed between Pd clusters and γ-Al2O3(110) was greater than that of α-Al2O3(0001) and γ-Al2O3(100). According to AIMD simulations and perpendicular displacements of Al and O atoms bound to the Pd cluster on the Al2O3 surface from the bare Al2O3 surface, coordinatively unsaturated Al3+ sites on γ-Al2O3(110) were more flexible than those on α-Al2O3(0001) and γ-Al2O3(100). The flexibility of γ-Al2O3(110) facilitated the formation of bonds with the Pd cluster, resulting in stronger MSIs. When the coordinatively unsaturated Al3+ sites were hydrated, the MSIs were found to be weakened.

DOI： 10.1021/acs.jpcc.3c02483

Scopus

Self-organized defect-rich RuMO<inf>x</inf> epitaxial layers (M = Mn, Fe, Co, Ni, Cu) for catalytic applications Reviewed

Oda A., Ichihashi R., Yamamoto Y., Sawabe K., Satsuma A.

Journal of Materials Chemistry A Vol. 11 ( 44 ) page： 23854 - 23866 2023.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Materials Chemistry A

Catalysts with epitaxially-grown metal oxide on the substrate have wide catalytic applications. However, manipulations of the surface reactivity remain challenging due to the lack of a simple strategy to engineer the morphology, surface atomic composition, and defect distribution of the epitaxial layer, limiting performance improvement. Here, we report a heterometal dopant-assisted epitaxial growth phenomenon for engineering the surface structure and reactivity of metal-oxide epitaxy. Our method focuses on the regulation of the lattice parameters of the epitaxy by heterometal doping. This approach can reduce the misfit and thereby stabilize the metal-oxide/substrate interface, resulting in epitaxial growth with a high aspect ratio, tunable surface atomic composition, and abundant defects. As a proof of concept, the doping effect of 3d transition metals (M = Mn, Fe, Co, Ni, Cu) on the epitaxial growth mechanism of RuOx on a rutile TiO2 substrate and their catalytic performance were investigated in the present study. It was found that simple co-impregnation of Ru and M nitrate solutions and subsequent calcination under an air atmosphere resulted in a unique set of epitaxial layers consisting of Ru and M oxides with atom thickness (RuMOx-ELs). These were grown by Frank-van der Merwe or Stranski-Krastanov growth modes. On the other hand, when only Ru nitrate was used for the catalyst preparation, the RuOx epitaxial nanoparticles were grown by the Volmer-Weber growth mode. The heterometal doping plays a pivotal role in tuning the lattice parameters of the epitaxy to reduce the misfit at the interface, driving the self-organization of the novel RuMOx-ELs even on a powder substrate without any special procedures. The RuMOx-ELs feature a high aspect ratio, and selectively exposed specific facets with abundant Ru-Olatt/Ovac-M local structures as the reactive sites. The surface concentration of Ru-Olatt/Ovac-M local structures and their reactivity depends on the kind of M; therefore, heterometal dopant-assisted epitaxial growth can be utilized to optimize the surface structure of the epitaxy for the target reaction. Its significance was proven by the fact that we have succeeded in creating the highest activity toward a low-temperature CO oxidation among the Ru-based catalysts reported in the literature.

DOI： 10.1039/d3ta05078e

Scopus

Breaking the Structure-Activity Relationship in Toluene Hydrogenation Catalysis by Designing Heteroatom Ensembles Based on a Single-Atom Alloying Approach Reviewed

Oda A., Fujita T., Yamamoto Y., Sawabe K., Satsuma A.

ACS Catalysis Vol. 13 ( 15 ) page： 10026 - 10040 2023.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Catalysis

Hydrogenation of toluene (TOL) to methylcyclohexane (MCH) is one of the hydrogen carrier systems desired for social integration. Supported Pt nanoparticle catalysts are effective for this application. However, Pt is rare, expensive, and in short supply, limiting its practical applications. Therefore, the key issue for TOL hydrogenation is how to substantially reduce the amount of Pt required for the catalyst. Because a specific ensemble of Pt atoms, that is dominantly formed on the surface of the Pt nanoparticle, is required for achieving higher catalytic performance, there is a limit to the number of precious Pt that can be conserved by simply reducing the particle size. The structure sensitivity established in the existing heterogeneous catalyst so far makes it difficult to design precious metal-conserving catalysts with both high activity and atomic efficiency. Here, a strategy for breaking the above limitations is reported. Our approach uses the heteroatom ensemble (HAE) on Pt single-atom alloyed 3d transition-metal nanoparticle catalysts (Pt1M SAAs, M = Co, Ni, Cu). The role of the TOL fixation/activation site is assigned to the atomic M sites on HAE, whereas the H2-activation site is to the Pt single-atom site on HAE. The atomic-scale division of roles within the HAE improves the efficiency of competitive adsorption of TOL/H2, which is important for boosting TOL hydrogenation. To maximize the synergistic effect at the adjacent sites, the atomic composition, geometric configuration, and electronic state of these active sites as well as the density of the HAE were tuned by the chemical composition and particle size of Pt1M SAAs. High activity was observed on the Pt1Co SAA with a particle size of 1.8 nm and Pt/Co molar ratio of 0.002. The Pt mass-specific activity reached 219 mol/gPt/h, which was 23 times higher than that in a conventional Pt nanoparticle-supported catalyst. Using a set of well-defined Pt1M SAAs, high-angle annular dark-field scanning transmission electron microscopy, Pt LIII-edge X-ray absorption fine structure spectroscopy, coupled with periodic density functional theory and ab initio molecular dynamics simulation, we proved the origin of the structure sensitivity at an atom-to-nanometer scale. The present work sheds light on the significance of regulations of the coordination environment of the Pt single-atom site, atomic composition, and particle size of Pt1M SAA for creating high activity, durability, and Pt-utilization efficiency for catalytic applications relevant to hydrogen carrier systems.

DOI： 10.1021/acscatal.3c02132

Scopus

Active coordination sites of Co spinel oxides for NO reduction by CO Reviewed

Ueda K., Tsuji M., Ohyama J., Satsuma A.

Catalysis Today Vol. 411-412 2023.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Catalysis Today

Cobalt spinel oxides, containing octahedral (Oh) and tetrahedral (Td) sites, exhibit high activity for NO reduction by CO. The active sites of cobalt spinel oxides for NO–CO reaction was identified using various cobalt spinel oxides having different CoOh/CoTd ratio. Comparing the CoOh/CoTd ratio determined by EXAFS fitting analysis and the rate of NO reduction, it was clarified that octahedral site is responsible for NO reduction by CO. Furthermore, synchrotron-based in-situ XAFS measurements unveiled the contribution of CoOh sites: The cobalt spinel oxides with high CoOh fraction were more easily reduced by CO to form oxygen vacancies than those with low CoOh fraction, and resulted in the higher activity for NO reduction by CO.

DOI： 10.1016/j.cattod.2022.06.031

Scopus

Enhanced CO oxidation by reversible structural variation of supported Ag nanoparticle catalyst from single to twin by CO treatment Reviewed

Tamura T., Ohyama J., Sawabe K., Satsuma A.

Catalysis Today Vol. 411-412 2023.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Catalysis Today

Twinned structure of metal nanoparticles can strongly affect catalysis because of its unique atomic alignment and bond strain in metal nanoparticles. Here, the twin and single crystal structures of supported Ag nanoparticles are controlled reversibly by gas treatment. The single crystal Ag nanoparticles were formed in Ag/Al2O3 by H2 treatment, and subsequent CO gas treatment changed the Ag particle structure to twin. The change in the Ag particle structure from single to twin caused enhancement of CO oxidation activity. In addition, the catalytic activity was reversibly changed from low to high by applying H2 and CO gas treatment to Ag/Al2O3. The kinetic analysis for CO oxidation revealed that the twin Ag nanoparticles have stronger CO adsorption energy than the single crystal ones, which is responsible for the enhanced CO oxidation activity of twin Ag nanoparticles.

DOI： 10.1016/j.cattod.2022.06.029

Scopus

Tandem Base-Metal Oxide Catalyst for Automotive Three-way Reaction: MnFe<inf>2</inf>O<inf>4</inf> for Preferential Oxidation of Hydrocarbon Reviewed Open Access

Maruichi K., Sakai R., Ueda K., Oda A., Satsuma A.

Catalysis Surveys from Asia Vol. 27 ( 1 ) page： 48 - 55 2023.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Catalysis Surveys from Asia

A combination of two base-metal oxides in tandem configuration can realize three-way reaction without platinum group metals. For this purpose, catalysts for hydrocarbon preferential oxidation (HC-PROX) and for NO reduction by CO are required. For the design of HC-PROX catalysts, competitive oxidation of propene and CO on spinel-type MFe2O4 (M = Co, Cu, Mg, Mn, Ni, Zn) was investigated. MnFe2O4 preferentially oxidized propene in the co-presence of CO showing the best propene oxidation activity. Among the series of MFe2O4, the activity controlling factor was correlated to the M-O bond energy of the second metal oxides, and the preference for HC oxidation was dependent on the electronegativity of the second ion. A tandem catalyst using MnFe2O4 for HC-PROX and CuCo2O4 for NO-CO reaction showed TWC activity comparable to a Rh/CeO2.

DOI： 10.1007/s10563-022-09373-9

Scopus

Exploring the framework of small pore zeolites for passive NOx adsorption Reviewed

Amen, T.W.M., Washiyama, S., Oda, A., Ohtsu, T., Satsuma, A., Tsunoji, N.

Microporous and Mesoporous Materials Vol. 361 2023

Language：English Publishing type：Research paper (scientific journal)

The use of a passive NOx adsorber (PNA) for NOx storage during the cold-start period is crucial for eliminating NOx emissions from the diesel exhaust. Palladium (Pd)-loaded zeolites have garnered significant attention owing to their high potential as PNA. In this study, small-pore zeolites with different frameworks were synthesized, and their structural characteristics and passive NOx adsorption abilities were investigated. Five zeolites, with CHA, AEI, AFX (low- and high- Si/Al ratio), and LEV framework structures, were synthesized by the hydrothermal conversion of faujasite-type (FAU) zeolite. Pd (1 wt%) was impregnated in combination with hydrothermal treatment. NOx adsorption and desorption behaviors were studied based on breakthrough NO adsorption and subsequent temperature-programmed desorption (TPD) experiments. Pd-loaded CHA, AEI, and LEV zeolites and high-silica AFX zeolites adsorbed approximately 93.88, 107.93, 97.57 and 106.53 μmol-NO g−1, respectively. On the other hand, the incorporation of Pd into AFX zeolite with a low Si/Al ratio led to significant hydrothermal damage and resulted in lower levels of adsorption and desorption capabilities. This demonstrates that hydrothermally stable small-pore zeolites on Pd-incorporation have great potential for passive NOx adsorption. The zeolite with different framework exhibited the different temperature range of NOx release. CHA, AEI, and high-silica AFX zeolites desorbed NOx in the low-temperature region (T < 250 °C), whereas the LEV zeolite showed a relatively high NOx desorption amount in the middle-temperature region (250 °C < T < 350 °C).

DOI： 10.1016/j.micromeso.2023.112746

Scopus

Surface modification of MCr<inf>2</inf>O<inf>4</inf> (M = Mg and Zn) by Cu-Doping: Theoretical prediction and experimental observation of enhanced catalysis for CO oxidation Open Access

Zhao P., Ueda K., Sakai R., Ehara M., Satsuma A., Sakaki S.

Applied Surface Science Vol. 605 2022.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Applied Surface Science

We theoretically investigated surface modification of MCr2O4 (M = Mg and Zn) by Cu-doping and doping effects on catalytic activity for CO oxidation. DFT + U calculations elucidated that Cu-dopants in MCr2O4(1 1 1) exist on the surface layer, CO oxidation by Cu-doped MCr2O4(1 1 1) occurs through Mars van Krevelen mechanism, rate-determining step (RDS) is the first CO2 desorption with oxygen vacancy (OV) formation, and the catalytic activity is enhanced very much by Cu-doping. Also, we experimentally observed that CO conversion was dramatically improved to 70% by the Cu-doped ZnCr2O4 from 5.2% by non-doped ZnCr2O4 at 300 °C. Bader charge analysis and difference density map show that M atom on the MCr2O4 surface receives electron density from the dissociating O atom in the OV formation step and the Cu-dopant can receive more electron density than Mg and Zn atoms to facilitate the OV formation and accelerate the first CO2 desorption(RDS). This larger capability of Cu-dopant for receiving electron density results from the facts that the Cu atom has large electronegativity and + I oxidation state besides + II in metal oxide but Mg and Zn have small electronegativity and only + II oxidation state.

DOI： 10.1016/j.apsusc.2022.154681

Scopus

Highly efficient CO-assisted conversion of methane to acetic acid over Rh-encapsulated MFI zeolite prepared using RhCl<inf>3</inf> molten salt

Oda A., Horie M., Murata N., Sawabe K., Satsuma A.

Catalysis Science and Technology Vol. 12 ( 18 ) page： 5488 - 5494 2022.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Catalysis Science and Technology

Direct catalytic conversion of methane to value-added chemicals with a high reaction rate and selectivity under mild conditions remains a great challenge. Rh-supported zeolite is one of the promising heterogeneous catalysts capable of selectively oxidizing methane to acetic acid using carbon monoxide and oxygen at low temperatures. However, the difficulty in the preparation of the catalytically active species, i.e., zeolite-confined RhI single-atom sites, has limited the mass activity. Here, we successfully prepared a highly-active Rh-containing zeolite using RhCl3 molten salt. By high-temperature treatment of the physically-mixed H+-MFI zeolite and bulk RhCl3, the RhCl3 molten salt was formed under in situ conditions and then diffused into the zeolite pores, resulting in being trapped within the zeolite cavity via host-guest interaction and ion-exchange with H+. The encapsulated RhCl3 species are efficiently dispersed with the formation of RhI single-atom species as the active sites in the catalytic reaction, boosting the direct conversion of methane to acetic acid with a record turnover frequency (592 mol molRh−1 h−1) and yield (14.6 mmol gcat−1 h−1) with high selectivity (76.9%).

DOI： 10.1039/d2cy01471h

Scopus

Orbital Trap of Xenon: Driving Force Distinguishing between Xe and Kr Found at a Single Ag(I) Site in MFI Zeolite at Room Temperature

Oda A., Kouzai H., Sawabe K., Satsuma A., Ohkubo T., Gotoh K., Kuroda Y.

Journal of Physical Chemistry C Vol. 126 ( 19 ) page： 8312 - 8326 2022.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Physical Chemistry C

Noble gas (Ng) elements are stable because of their octet electronic configuration, and thus Ng capture and purification are highly challenging. Here, we show a new concept for these applications: an orbital trap for Xe. This concept was found in Xe adsorption/separation processes at room temperature (RT) at the single Ag(I) site in MFI zeolite. Experiments and calculations showed the zeolite lattice-coordinated Ag(I) single ion has excellent electron-accepting nature and thereby induces the Xe 5p → Ag(I) 5s donation orbital interaction, forming a stable σ-bond with Xe even in the lower-pressure region and at RT. By contrast, the stable σ-bond for Kr adsorption is not established at RT because of the instability of the orbital interactions of the Kr 4p → Ag(I) 5s donation, as reflected from the relatively high energy of the Kr 4p orbital. Thus, the single Ag(I) site allows it to distinguish between Xe and Kr at RT; the Xe separation from the Xe/Kr gas mixture was achieved at RT using the Ag/MFI containing a high concentration of single Ag(I) sites. Our findings suggest that the orbital Xe trap using the local structure of porous materials shows promise as an efficient approach to selectively collect Xe (air concentration 0.087 ppm only). It will help to expand the range of applications of the costly Xe.

DOI： 10.1021/acs.jpcc.2c01515

Scopus

High Pt-mass activity of Pt<sup>IV</sup><inf>1</inf>/β-MnO<inf>2</inf> surface for low-temperature oxidation of CO under O<inf>2</inf>-rich conditions

Nagata T., Oda A., Yamamoto Y., Ichihashi R., Sawabe K., Satsuma A.

Catalysis Science and Technology Vol. 12 ( 9 ) page： 2749 - 2754 2022.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Catalysis Science and Technology

A Pt-based CO oxidation catalyst that works even at low temperatures is desirable for industrial applications; however, its development is highly challenging because of Pt's high affinity toward CO. Here, we develop a PtIV single-atom/β-MnO2 composite metal-oxide surface (PtIV1/β-MnO2). Single PtIV sites were stably formed on the high surface β-MnO2 by strong interaction with MnIV defect sites. The resulting PtIV-O-MnIV local structures served the lattice oxygens as an oxidant to catalyze low-temperature oxidation of CO. PtIV1/β-MnO2 was highly resistant to CO poisoning because of the high-valence state of the PtIV single-atom sites. Aided by these geometric and electronic features, the CO oxidation was catalyzed with reaction rates of 0.676 and 0.206 molCO h−1 gPt−1 at 25 °C and 0 °C, respectively, under the O2-rich conditions (O2 : CO ratio of 66.7). These are record rates in the literature for Pt-based catalyst application for low-temperature CO oxidation under near atmospheric conditions.

DOI： 10.1039/d2cy00677d

Scopus

Preferential oxidation of propene in gasoline exhaust conditions over supported vanadia catalysts Open Access

Sakai R., Ueda K., Ohyama J., Oda A., Deguchi K., Ohki S., Satsuma A.

Journal of Catalysis Vol. 408 page： 261 - 269 2022.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Catalysis

For the design of a high-performance platinum group metal-free three-way catalyst, we propose a new C3H6-preferential oxidation (C3H6-PROX) catalyst under stoichiometric automobile exhaust gas (NO–CO–C3H6–O2) using supported vanadia catalysts. Among various V2O5 supported catalysts, V2O5/TiO2 (anatase, coverage of around one monolayer) showed the best activity for C3H6-PROX with preferable formation of CO. The tandem catalyst combination using V2O5/TiO2 as the upstream C3H6-PROX catalyst and Cu/CeO2 as the downstream NO–CO reaction catalyst showed comparable activity for NO reduction as a Rh/ZrO2 catalyst. The reaction mechanism of C3H6 oxidation was analyzed using in situ Infrared spectroscopy. The C3H6 oxidation progressed with the formation of surface acetate as an intermediate, and acetate consumption was the key step of C3H6 oxidation. It is suggested that the Brønsted acid promoted the cleavage of the C–C bond of acetate, therefore, the number of Brønsted acid sites is one of the critical factors for the higher performance of C3H6-PROX catalysts.

DOI： 10.1016/j.jcat.2022.03.012

Scopus

Theoretical Study on Carbon Monoxide Adsorption on Unsupported and γ-Al<inf>2</inf>O<inf>3</inf>-Supported Silver Nanoparticles: Size, Shape, and Support Effects Open Access

ACS Omega Vol. 7 ( 5 ) page： 4405 - 4412 2022.2

Enhancement of toluene hydrogenation activity of supported Pt nanoparticles with increasing the crystallinity of Pt

Applied Catalysis A: General Vol. 629 page： 118425 2022.1

Rational design of ZSM-5 zeolite containing a high concentration of single Fe sites capable of catalyzing the partial oxidation of methane with high turnover frequency

Akira Oda, Koshiro Aono, Naoya Murata, Kazumasa Murata, Masazumi Yasumoto, Nao Tsunoji, Kyoichi Sawabe, Atsushi Satsuma

CATALYSIS SCIENCE & TECHNOLOGY Vol. 12 ( 2 ) page： 542 - 550 2022.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Iron-containing zeolites possess active sites capable of catalyzing the low-temperature partial oxidation of methane using hydrogen peroxide as an environmentally benign oxidant. However, only a trace number of active sites have been found in zeolites so far. The high turnover frequency was limited to low loading samples, resulting in an upper limit of similar to 50 mmol g(cat)(-1) h(-1) yield of C1 oxygenates. In this study, we synthesized a ZSM-5 catalyst containing a high concentration of single Fe sites with a high turnover frequency, and achieved a conversion of methane to C1 oxygenates of similar to 200 mmol g(cat)(-1) h(-1) yield. It was important to use ZSM-5 as a carrier, which can be synthesized by hydrothermal treatment of aluminosilicate gel containing only tetra-propyl ammonium cations as the structure-directing agent (SDA). This ZSM-5 carrier has a large fraction of local environments possessing the nearest framework AlO4 tetrahedra required for the fixation of Fe cations in the mononuclear state while suppressing the co-generation of oligomeric Fe sites, making it possible to design a reaction field for the highly efficient partial oxidation of methane. The findings in the present study clearly showed that the fraction of single Fe cations and the Al distribution in the zeolite matrix are powerful activity descriptors for this class of materials. Furthermore, Al-distribution modification based on previously-established protocols, i.e., rational choice of an SDA used in the zeolite synthesis, is a meaningful way to tune not only the fabrication efficiency of single Fe cations but also the catalytic performance of Fe/ZSM-5 catalysts.

DOI： 10.1039/d1cy01987b

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Theoretical Study of the Propene Combustion Catalysis of Chromite Spinels: Reaction Mechanism and Relation between the Activity and Electronic Structure of Spinels

Zhao P., Ehara M., Satsuma A., Sakaki S.

Journal of Physical Chemistry C Vol. 125 ( 47 ) page： 25983 - 26002 2021.12

Structure-Property Relationships of Pt-Sn Nanoparticles Supported on Al2O3for the Dehydrogenation of Methylcyclohexane

Kazumasa Murata, Natsuki Kurimoto, Yuta Yamamoto, Akira Oda, Junya Ohyama, Atsushi Satsuma

ACS Applied Nano Materials Vol. 4 ( 5 ) page： 4532 - 4541 2021.5

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

The structure-catalytic property relationships of Al2O3-supported Pt-Sn nanoparticles (Pt-Sn/Al2O3) in the dehydrogenation of methylcyclohexane (MCH) were investigated by varying the Sn/Pt ratios of the catalysts. The initial activity and the deactivation rate of the Pt-Sn/Al2O3 catalysts in the MCH dehydrogenation decreased in line with an increase in the Sn/Pt ratio from 0 to 3. The Pt-Sn/Al2O3 catalyst with a Sn/Pt ratio of 2 showed good activity, durability, and toluene selectivity in the MCH dehydrogenation among the series of catalysts. The dispersion of Pt in the Pt-Sn/Al2O3 catalysts was observed to decrease with an increase in the Sn/Pt ratio. Structural changes in the catalysts from Pt-Sn clusters to intermetallic Pt3Sn and PtSn nanoparticles were also observed using scanning transmission electron microscopy and X-ray diffraction. According to structural analysis using X-ray absorption fine-structure spectroscopy and infrared spectroscopy using carbon monoxide as a probe, the electron density of Pt increased, and the fraction of Pt-Pt adjacent sites decreased with an increase in the Sn/Pt ratio. Comparing the catalytic properties and the structures of the Pt-Sn/Al2O3 catalysts, their initial activities were correlated with the dispersion of Pt. In addition, the durability and selectivity of the catalysts were enhanced due to an increase in the electron density of Pt and a decrease in the number of Pt-Pt adjacent sites. Overall, the properties of the catalysts in the MCH dehydrogenation are determined by the local structure of Pt atoms rather than the crystal structure of the Pt-Sn alloy nanoparticles on Al2O3.

DOI： 10.1021/acsanm.1c00128

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Relationship between penta-coordinated Al3+ sites in the Al2O3 supports and CH4 combustion activity of Pd/Al2O3 catalysts dagger

Kazumasa Murata, Takumi Shiotani, Junya Ohyama, Ryutaro Wakabayashi, Hirokazu Maruoka, Tatsuo Kimura, Atsushi Satsuma

CATALYSIS SCIENCE & TECHNOLOGY Vol. 11 ( 7 ) page： 2374 - 2378 2021.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Pd/Al2O3 catalysts were prepared using various Al2O3 supports with different structural features such as crystalline phase and crystallinity related to Al3+ coordination, revealing a significant insight into the methane (CH4) combustion activity of Pd nanoparticles with the fraction of penta-coordinated Al3+ sites in the Al2O3 supports.

DOI： 10.1039/d1cy00098e

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17O-ESR Evidence for Zeolite Matrix Isolation of a Square Planar ZnO3 Ring Radical with C2v Symmetry

Akira Oda, Jun Kumagai, Kyoichi Sawabe, Takahiro Ohkubo, Yasushige Kuroda, Atsushi Satsuma

The Journal of Physical Chemistry C Vol. 125 ( 9 ) page： 5136 - 5145 2021.3

Kinetic analysis of Ag particle redispersion into ZSM-5 in the presence of coke usingin situXAFS

Kazumasa Murata, Junya Ohyama, Atsushi Satsuma

Catalysis Science and Technology Vol. 11 ( 2 ) page： 506 - 515 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed usingin situX-ray absorption fine structure (XAFS) spectroscopy. The dynamics of Ag particle redispersion into the ZSM-5 pores were evaluated by linear combination fitting (LCF) of the X-ray absorption near edge structure (XANES) spectra. In addition, the behavior of coke combustion in Ag-ZSM-5 was observed by thermogravimetric analysis (TGA). The rate constant of Ag particle redispersion was smaller than that of coke combustion at ≥500 °C, but it was three times larger than that of coke combustion at &lt
500 °C. According to27Al magic angle spinning (MAS) nuclear magnetic resonance (NMR), the Ag+ions in the ZSM-5 pores improved the hydrothermal stability of Ag-ZSM-5. Therefore, a two-step regeneration process, in which the Ag particle redispersion proceeded first at low temperature (&lt
500 °C) followed by a complete combustion of the coke at high temperature (≥500 °C) to prolong the catalyst lifetime, was used.

DOI： 10.1039/d0cy01989e

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Theoretical insight into oxidation catalysis of chromite spinel MCr<inf>2</inf>O<inf>4</inf> (M = Mg, Co, Cu, and Zn): Volcano plot for oxygen-vacancy formation and catalytic activity

Journal of Catalysis Vol. 393 page： 30 - 41 2021.1

Selective hydrogenation of C=C bond in cinnamaldehyde on Pd step sites of Pd/Al2O3

Kazumasa Murata, Takumi Shiotani, Junya Ohyama, Atsushi Satsuma

Chemistry Letters Vol. 50 ( 4 ) 2021

Language：English Publishing type：Research paper (scientific journal) Publisher：Chemical Society of Japan

We found a positive correlation between C=C selective hydrogenation activity of cinnamaldehyde (CAL) and the fraction of the Pd step site on Pd nanoparticles. Owing to a high fraction of step sites, Pd/θ-Al2O3 catalysts with Pd particle size of 510 nm were highly active for the C=C selective hydrogenation of CAL.

DOI： 10.1246/CL.200856

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Improvement of hydrogen oxidation reaction in anion exchange membrane fuel cells with ruthenium-based nanoparticle catalysts Open Access

Junya Ohyama, Atsushi Satsuma

Journal of the Japan Petroleum Institute Vol. 64 ( 4 ) page： 166 - 171 2021

Language：English Publishing type：Research paper (scientific journal) Publisher：Japan Petroleum Institute

Catalysts to improve the hydrogen oxidation reaction (HOR) were developed via control of Ru nanoparticle size, alloying Ru with Ir, and surface modification of metal nanoparticles. The performance of these developed anode catalysts for anion exchange membrane fuel cells had improved, which is dependent on the hydrogen binding energy and the bifunctional mechanism. Surface modification of metal nanoparticles further enhanced the HOR activity based on the bifunctional mechanism. Such surface medication could form reactive OH species and remove surface poisoning of the hydrogen adsorption sites.

DOI： 10.1627/jpi.64.166

Open Access

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Tuning the oxygen release properties of CeO2-based catalysts by metal-support interactions for improved gasoline soot combustion

Ryota Ashikaga, Kazumasa Murata, Tetsuya Ito, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

Catalysis Science and Technology Vol. 10 ( 21 ) page： 7177 - 7185 2020.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

To develop highly active soot combustion catalysts for gasoline direct injection exhausts under low oxygen concentration conditions, CeO2 supported-metal catalysts (M/CeO2, M = Mn, Fe, Co, Ni, Cu, Rh, Pd, and Ag) were examined. Among the catalysts tested, Cu/CeO2 and Rh/CeO2 displayed the highest soot combustion activity. By comparing the activities of Cu-based catalysts with and without a Cu-CeO2 interface, the importance of such an interface for soot combustion was inferred. The oxygen release rate of CeO2-based catalysts, enhanced by metal-CeO2 interactions, was indicated as the controlling factor of catalytic activity. The soot oxidation activity and oxygen release rate were also demonstrated to correlate with metal-oxygen bond energy. Based on the redox properties and structural characteristics of CeO2-based catalysts, loading CeO2 with Cu or Rh, which have moderate M-O bond energy, was concluded to be optimal both in terms of the dispersion of supported-metal species and reducibility of the CeO2-based catalyst.

DOI： 10.1039/d0cy01294g

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How to Constrain Metal-Oxyl Bonds on a Solid Surface? Lesson from Isovalent Zn(II)-Oxyl and Ga(III)-Oxyl Bonds Isolated in Zeolite Matrix

Oda A., Tanaka T., Sawabe K., Satsuma A.

Journal of Physical Chemistry Letters Vol. 11 ( 21 ) page： 9426 - 9431 2020.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Physical Chemistry Letters

Isolation of the atomic O radical anion bound to a metal ion (metal-oxyl) on solid surfaces is highly desirable for an understanding of how we should design the surface structure for using oxyl as the reactive site. Owing to the analytical difficulty of oxyl, however, even identification of oxyl remains scarce. Herein, we report isovalent ZnII-oxyl and GaIII-oxyl bonds isolated in the zeolite matrix. Close similarities in reactivity, spectroscopic property, and bonding nature were observed between them, but their site requirements were entirely different; the former is generated at the monovalent ion-exchangeable site, whereas the latter at the divalent ion-exchangeable site. This study strongly suggests that tuning the polarization of the metal-oxygen bond using the charge-controlled lattice oxygens is a useful way to constrain surface metal-oxyl bonds.

DOI： 10.1021/acs.jpclett.0c02980

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Spectroscopic Evidence of Efficient Generation of Dicopper Intermediate in Selective Catalytic Reduction of NO over Cu-Ion-Exchanged Zeolites

Oda A., Shionoya H., Hotta Y., Takewaki T., Sawabe K., Satsuma A.

ACS Catalysis Vol. 10 ( 20 ) page： 12333 - 12339 2020.10

Methane Combustion over Pd/Al2O3Catalysts in the Presence of Water: Effects of Pd Particle Size and Alumina Crystalline Phase

Kazumasa Murata, Junya Ohyama, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

ACS Catalysis Vol. 10 ( 15 ) page： 8149 - 8156 2020.8

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

The effects of the Pd particle size and the Al2O3 crystalline phase of Pd/Al2O3 catalysts on the CH4 combustion in the presence of H2O were investigated. According to X-ray absorption fine structure (XAFS) measurements, it was revealed that, during the CH4 combustion, the Pd nanoparticles existed on the Al2O3 support as a PdO phase, while the crystallinity of PdO depended on the Pd particle size. On the basis of X-ray diffraction (XRD), amorphous PdO particles with a size of &lt
7 nm exhibited low activity for CH4 combustion. In contrast, as the Pd particle size increased, larger crystalline PdO particles (&gt
7 nm) were formed, which were highly active for CH4 combustion. Comparing the effects of the different Al2O3 crystalline phases, Pd/α-Al2O3 was proved to be more resistant to deactivation by H2O than Pd/γ-Al2O3 and Pd/θ-Al2O3. Moreover, according to H2O temperature-programmed desorption (TPD) and infrared (IR) measurements, since α-Al2O3 was relatively hydrophobic compared to γ-Al2O3 and θ-Al2O3, a faster and reversible adsorption/desorption of OH/H2O species was achieved, while the H2O poisoning on PdO species in the vicinity was limited.

DOI： 10.1021/acscatal.0c02050

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Reductive conversion of 5-hydroxymethylfurfural to 1,2,6-hexanetriol in water solvent using supported Pt catalysts

Kataoka Hiroto, Kosuge Daichi, Ogura Keiji, Ohyama Junya, Satsuma Atsushi

CATALYSIS TODAY Vol. 352 page： 60-65 - 65 2020.8

Effects of carbon number and bond saturation on hydrocarbon combustion over a diesel oxidation catalyst

Akihiro Tsuchiya, Sota Masaoka, Junya Ohyama, Kyoichi Sawabe, Atsushi Satsuma

Catalysis Science and Technology Vol. 10 ( 12 ) page： 3868 - 3874 2020.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

One of the problems in a diesel oxidation catalyst is its insufficient activity for injected diesel fuel at low temperatures caused by strong adsorption of hydrocarbons. This study systematically clarified the poisoning effect of various hydrocarbons having carbon numbers from 3 to 16. As the carbon number in alkanes increased, the light-off temperature over a Pt-Pd/Al2O3 catalyst gradually shifted to a lower temperature. While alkenes and aromatics showed an opposite trend, the light-off shifted to a higher temperature as the carbon number increased. In situ FTIR spectra indicated that the amount of adsorbed hydrocarbons on the metal surface increased with the increase in the carbon number of alkanes and alkenes. Kinetic analysis showed that the reaction orders with respect to O2 were below zero in light alkane combustion, while those with respect to hydrocarbons were zero or lower in alkene and aromatic combustion. The shift of the light-off temperatures was rationalized by competitive adsorption of hydrocarbons and oxygen. This journal is

DOI： 10.1039/d0cy00017e

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Selective Hydrogenation of Cinnamaldehyde over the Stepped and Plane Surface of Pd Nanoparticles with Controlled Morphologies by CO Chemisorption

Kazumasa Murata, Keiji Ogura, Junya Ohyama, Junya Ohyama, Kyoichi Sawabe, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma, Atsushi Satsuma

ACS Applied Materials and Interfaces Vol. 12 ( 23 ) page： 26002 - 26012 2020.6

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

Carbon monoxide (CO) molecules are attracting attention as capping agents that control the structure of metal nanoparticles. In this study, we aimed to control the shape and surface structure of Pd particles by reducing the supported Pd precursor with CO. The reduction of Pd nanoparticles with CO promoted the exposure of step sites and generated spherical and concave-tetrahedral Pd particles on carbon and SiO2 supports. On the other hand, conventional H2-reduced Pd particles show a flattened shape. The preferential exposure of the step sites by the adsorbed CO molecules was supported by the density functional theory-calculated surface energy and the Wulff construction. Morphology- and surface-controlled Pd nanoparticles were used to study the surface structure and morphology effects of Pd nanoparticles on cinnamaldehyde (CAL) hydrogenation. With an increase in the fraction of step sites on Pd nanoparticles, the hydrogenation activity and selectivity of hydrocinnamaldehyde (HCAL) increased. On step sites, the adsorption of the C-C bond of CAL proceeded preferentially, and HCAL was efficiently and selectively generated.

DOI： 10.1021/acsami.0c05938

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PubMed

In Situ Spectroscopic Studies on the Redox Cycle of NH3-SCR over Cu-CHA Zeolites Open Access

Liu Chong, Kubota Hiroe, Amada Takehiro, Kon Kenichi, Toyao Takashi, Maeno Zen, Ueda Kakuya, Ohyama Junya, Satsuma Atsushi, Tanigawa Takuya, Tsunoji Nao, Sano Tsuneji, Shimizu Ken-ichi

CHEMCATCHEM Vol. 12 ( 11 ) page： 3050-3059 - 3059 2020.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The selective catalytic reduction of NO with ammonia (NH3-SCR) catalyzed by Cu-CHA zeolites is thoroughly investigated using in situ spectroscopic experiments combined with on-line mass spectroscopy (MS) under steady-state NH3-SCR conditions and transient conditions for Cu(II)/Cu(I) redox cycles. Quantitative analysis of the in situ XANES spectra of Cu-CHA under steady-state conditions of NH3-SCR show that NH3-coordinated Cu(II) species is the dominant Cu species at low temperatures (100-150 degrees C). At higher temperatures, Cu(II) species and [Cu(NH3)(2)](+) complex coexist, possibly because the rate of the Cu(II) -> Cu(I) reduction step is comparable to that of the Cu(I)-> Cu(II) oxidation step. In situ XANES, IR/MS, and UV-vis/MS experiments on the reduction half cycle demonstrate that the reduction of Cu(II) species occurs via the reaction of NH3-liganded Cu(II) with NO to yield N-2 and H2O. For the oxidation half cycle, in situ XANES experiments of Cu(I) oxidation in 10 % O-2 at 200 degrees C indicate that an increased density in CHA zeolite exhibits a higher oxidation rate. In situ UV-vis experiments of Cu(I) reoxidation using different mixtures of oxidant feed gas demonstrate the key role of O-2 in the oxidation cycle. It is suggested that the reoxidation of Cu(I) to Cu(II) species occurs with only O-2 as the oxidant, and a high Cu density in CHA zeolite promotes SCR activity by enhancing the oxidative activation of Cu(I) to Cu(II) during the catalytic cycle.

DOI： 10.1002/cctc.202000024

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Enhancement of Alkaline Hydrogen Oxidation Reaction of Ru-Ir Alloy Nanoparticles through Bifunctional Mechanism on Ru-Ir Pair Site

Ishikawa Kazutomo, Ohyama Junya, Okubo Keiichi, Murata Kazumasa, Satsuma Atsushi

ACS APPLIED MATERIALS & INTERFACES Vol. 12 ( 20 ) page： 22771-22777 - 22777 2020.5

Removal of Surface Poisoning Improves Hydrogen Oxidation Performance of Pt Catalysts under Basic Conditions

Ohyama Junya, Okubo Keiichi, Ishikawa Kazutomo, Saida Takahiro, Yamamoto Yuta, Arai Shigeo, Satsuma Atsushi

ACS APPLIED ENERGY MATERIALS Vol. 3 ( 2 ) page： 1854-1859 - 1859 2020.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Anion exchange membrane fuel cells (AEMFCs) have been developed to the extent that the cell performance is nearing that of conventional proton exchange membrane fuel cells. For further improvement of AEMFC cell performance, it is necessary to develop the catalysis of hydrogen oxidation reactions (HORs) under basic conditions at the anode. Here, significant poisoning of Pt/C under basic conditions is demonstrated by electrochemical active surface area (ECSA) analysis using not only electrochemical measurement but also in situ Pt L-3-edge X-ray adsorption spectroscopy (XAS). Furthermore, the in situ XAS analysis reveals that the surface modification of Pt/C with another metal species improves the ECSA of the Pt nanoparticles by removal of the surface poisoning, which contributes to the enhanced HOR performance of the modified Pt/C catalysts. Therefore, the removal of poisoning is proposed as a mechanism for improving the HOR on Pt-based catalysts.

DOI： 10.1021/acsaem.9b02274

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In situ/operando spectroscopic studies on NH<inf>3</inf>–SCR reactions catalyzed by a phosphorus-modified Cu-CHA zeolite Open Access

Hiroe Kubota, Chong Liu, Takehiro Amada, Kenichi Kon, Takashi Toyao, Zen Maeno, Kakuya Ueda, Atsushi Satsuma, Nao Tsunoji, Tsuneji Sano, Kenichi Shimizu

Catalysis Today Vol. 376 page： 73 - 80 2020

Language：English Publishing type：Research paper (scientific journal)

The modification of Cu-exchanged zeolites with phosphorus represents a promising method to enhance their hydrothermal stability, which is of pivotal importance for catalysts that promote the selective catalytic reduction of NO with ammonia (NH –SCR). In this study, we investigated the reaction mechanism of NH –SCR catalyzed by a phosphorus-modified CHA zeolite that contains active Cu species (Cu-P-CHA), and assessed the effect of the phosphorus modification on the hydrothermal stability of the catalyst by employing in situ/operando spectroscopic methods. In their entirety, the combined results from in situ/operando IR, UV–vis, and XANES experiments revealed that the NH –SCR process over Cu-P-CHA proceeds via the reduction of Cu(II) to Cu(I) followed by a reoxidation of Cu(I) to Cu(II). In addition, we found that the phosphorus modification improved the hydrothermal durability of the catalyst by retaining a higher amount of the redox-active Cu species and the zeolite framework. 3 3 3

DOI： 10.1016/j.cattod.2020.07.084

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Exploiting Metal-Support Interactions to Tune the Redox Properties of Supported Pd Catalysts for Methane Combustion Reviewed

Murata, Kazumasa, Kosuge, Daichi, Ohyama, Junya, Mahara, Yuji, Yamamoto, Yuta, Arai, Shigeo, Satsuma, Atsushi

ACS Catalysis Vol. 10 ( 2 ) page： 1381 - 1387 2020

Gas-phase synthesis of morphology-controlled Pt nanoparticles and their impact on cinnamaldehyde hydrogenation

Kato Sosuke, Ohyama Junya, Machida Masato, Satsuma Atsushi

CATALYSIS SCIENCE & TECHNOLOGY Vol. 9 ( 9 ) page： 2097-2102 - 2102 2019.5

Tandem Base-Metal Oxide Catalyst: Superior NO Reduction Performance to the Rh Catalyst in NO-C3H6-CO-O-2

Ueda Kakuya, Tsuji Masashi, Ohyama Junya, Satsuma Atsushi

ACS CATALYSIS Vol. 9 ( 4 ) page： 2866-2869 - 2869 2019.4

Surface modification of Pt nanoparticles with other metals boosting the alkaline hydrogen oxidation reaction

Okubo Keiichi, Ohyama Junya, Satsuma Atsushi

CHEMICAL COMMUNICATIONS Vol. 55 ( 21 ) page： 3101-3104 - 3104 2019.3

Enhanced alkaline hydrogen oxidation reaction by modifying Pt nanoparticle surface with another metal

Ohyama J., Okubo K., Satsuma A.

ECS Transactions Vol. 92 ( 8 ) page： 733 - 738 2019

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ECS Transactions

The cell performance of anion exchange membrane fuel cells (AEMFCs) has been getting closer to that of proton exchange membrane fuel cells (PEMFCs) by improvement of hydrogen oxidation reaction (HOR) catalysts on anodes with the help of the state-of-the-art AEMs having high ion conductivity. However, development of the alkaline HOR catalysts is still demanded to reduce the usage of precious metals on AEMFC anode. Here, Pt/C catalyst is modified to improve the HOR activity using fifteen metals on the group 4-11 of the 4th and 5th period in the periodic table except for Tc, i.e., Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Pd, Ag. In addition, the hydrogen binding energy of modified Pt/C and the oxophilicity of modifying metals are evaluated to reveal the mechanism of improved/lowered HOR activity.

DOI： 10.1149/09208.0733ecst

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In situ and operando analysis of environmental catalysts - Studies on reaction mechanism and active site

Murata K., Ueda K., Mahara Y., Ohyama J., Satsuma A.

Catalysis Vol. 31 page： 242 - 266 2019

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Catalysis

In situ and operando analyses are the methods to observe the real features of catalysts under the reaction conditions. These methods can clarify the dynamics of active species of catalysts and reaction scheme on catalyst surface through transient response method, kinetic study, temperature dependence of catalysts and products, and so on. In this review, progress in in situ and operando analyses is summarized with emphasis on environmental catalysts, i.e., catalysts for combustion, selective reduction of NO, automotive three-way catalysis, and related materials.

DOI： 10.1039/9781788016971-00242

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Structure-Activity Relationship of Iron Oxides for NO Reduction in the Presence of C3H6, CO, and O-2 Reviewed

Ueda, Kakuya, Ohyama, Junya, Sawabe, Kyoichi, Satsuma, Atsushi

Chemistry - A European Journal Vol. 25 ( 61 ) page： 13964 - 13971 2019

Shape Control Preparation of Supported Platinum Nano-octahedra by Ethylene Treatment for Enhancement of Selective Hydrogenation of Cinnamaldehyde Reviewed

Ohyama, Junya, Kato, Sosuke, Machida, Masato, Satsuma, Atsushi

Chemistry Letters Vol. 48 ( 10 ) page： 1203 - 1205 2019

Quantum Chemical Computation-Driven Development of Cu-Shell-Ru-Core Nanoparticle Catalyst for NO Reduction Reaction Reviewed

Ohyama, Junya, Shibano, Jumpei, Satsuma, Atsushi, Fukuda, Ryoichi, Yamamoto, Yuta, Arai, Shigeo, Shishido, Tetsuya, Asakura, Hiroyuki, Hosokawa, Saburo, Tanaka, Tsunehiro

The Journal of Physical Chemistry C Vol. 123 ( 33 ) page： 20251 - 20256 2019

Identification of active sites in CO oxidation over a Pd/Al2O3 catalyst Reviewed

Murata, Kazumasa, Eleeda, Eleen, Ohyama, Junya, Yamamoto, Yuta, Arai, Shigeo, Satsuma, Atsushi

Physical Chemistry Chemical Physics Vol. 21 ( 33 ) page： 18128 - 18137 2019

Twinned/untwinned catalytic gold nanoparticles identified by applying a convolutional neural network to their Hough transformed Z-contrast images

Yamamoto Yuta, Hattori Mizuki, Ohyama Junya, Satsuma Atsushi, Tanaka Nobuo, Muto Shunsuke

MICROSCOPY Vol. 67 ( 6 ) page： 321-330 - 330 2018.12

Synthesis of Supported Bimetal Catalysts using Galvanic Deposition Method

Mahara Y., Ohyama J., Sawabe K., Satsuma A.

Chemical Record Vol. 18 ( 9 ) page： 1306 - 1313 2018.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Chemical Record

Supported bimetallic catalysts have been studied because of their enhanced catalytic properties due to metal-metal interactions compared with monometallic catalysts. We focused on galvanic deposition (GD) as a bimetallization method, which achieves well-defined metal-metal interfaces by exchanging heterogeneous metals with different ionisation tendencies. We have developed Ni@Ag/SiO2 catalysts for CO oxidation, Co@Ru/Al2O3 catalysts for automotive three-way reactions and Pd−Co/Al2O3 catalysts for methane combustion by using the GD method. In all cases, the catalysts prepared by the GD method showed higher catalytic activity than the corresponding monometallic and bimetallic catalysts prepared by the conventional co-impregnation method. The GD method provides contact between noble and base metals to improve the electronic state, surface structure and reducibility of noble metals.

DOI： 10.1002/tcr.201700084

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Time Resolved in situ DXAFS Revealing Highly Active Species of PdO Nanoparticle Catalyst for CH<inf>4</inf> Oxidation

Mahara Y., Murata K., Ueda K., Ohyama J., Kato K., Satsuma A.

ChemCatChem Vol. 10 ( 16 ) page： 3384 - 3387 2018.8

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ChemCatChem

The highly active species of Pd/Al2O3 catalysts for methane combustion was revealed by in situ time-resolved dispersive X-ray absorption fine structure (DXAFS) spectroscopy. By using CH4 as a reduction agent, PdO in Pd/Al2O3 is reduced in a 2-step model involving Pd0 nucleation and growth of Pd0 domain in a PdO particle. Kinetic analysis of the 2-step model reduction of PdO nanoparticles leads to a suggestion that partial formation of Pd0 in a PdO particle accelerates methane combustion.

DOI： 10.1002/cctc.201800573

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Formation of Rhodium Metal Ensembles that Facilitate Nitric Oxide Reduction over Rhodium/Ceria in a Stoichiometric Nitric Oxide–Carbon Monoxide–Propene–Oxygen Reaction

Junya Ohyama, Takumi Nishiyama, Atsushi Satsuma

ChemCatChem Vol. 10 ( 7 ) page： 1651 - 1656 2018.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley Blackwell

A series of ceria-supported Rh nanoparticles (NPs) that have various particle sizes of 2–7 nm was prepared to investigate the size effect of Rh NPs on NO reduction in NO–CO–C3H6–O2 under stoichiometric conditions. The turnover frequency (TOF) for NO reduction on Rh NPs increased drastically according to their particle size. The strong size dependence of the TOF was attributed to the oxidation states of Rh NPs but not to particle geometries, which include fractions of surface local sites (e.g., corner, edge, plane) and the surface crystal structures (e.g., Rh(1 1 1), (1 0 0)). The variation of the TOF with the Rh metal fraction suggested that Rh metal ensembles are highly active species for NO reduction.

DOI： 10.1002/cctc.201701842

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Enhanced three way catalytic activity of NiFe2O4 by physically mixed metal oxides

Shiori Nagai, Kakuya Ueda, Junya Ohyama, Atsushi Satsuma

Catalysis Today Vol. 303 page： 40 - 45 2018.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

The NOx reduction activity of NiFe2O4 in automotive three-way catalysis was enhanced by physical mixing with CeO2, MgO, ZrO2, and Al2O3, while the mixing with TiO2 and Nb2O5 did not promoted the catalytic activity. On both pure NiFe2O4 and the physically mixed catalysts, NO was mainly reduced by C3H6 under the NO-C3H6-CO-O2 reaction conditions, because the temperature dependence of NO conversion in NO-C3H6-CO-O2 reaction was the same as that in NO-C3H6-O2 reaction. The in-situ FT/IR measurement revealed that the NO reduction proceeded with (1) partial oxidation of C3H6 to surface carboxylates, i.e., acetate and formate as good reductants for NO, and (2) reduction of NO by surface carboxylates. The metal oxide additives did not have catalytic activity for partial oxidation of C3H6 nor for NO oxidation to NO2, except CeO2. The main promotion effect was attributed to storage and release of surface carboxylates by metal oxide additives.

DOI： 10.1016/j.cattod.2017.07.026

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Direct Synthesis of Lactams from Keto Acids, Nitriles, and H2 by Heterogeneous Pt Catalysts

S. M.A.H. Siddiki, Abeda S. Touchy, Ashvini Bhosale, Takashi Toyao, Yuji Mahara, Junya Ohyama, Atsushi Satsuma, Ken-Ichi Shimizu

ChemCatChem Vol. 10 ( 4 ) page： 789 - 795 2018.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley Blackwell

We report herein the first general catalytic system for the direct synthesis of N-substituted γ- and δ-lactams by reductive amination/cyclization of keto acids (including levulinic acid) with nitriles and H2 under mild conditions (7 bar H2, 110 °C, solvent free). The most effective catalyst, Pt and MoOx co-loaded TiO2 (Pt-MoOx/TiO2), shows a wide substrate scope, high turnover number (TON), and good reusability.

DOI： 10.1002/cctc.201701355

Scopus

Dynamic Behavior of Rh Species in Rh/Al<inf>2</inf>O<inf>3</inf> Model Catalyst during Three-Way Catalytic Reaction: An Operando X-ray Absorption Spectroscopy Study

Hiroyuki Asakura, Saburo Hosokawa, Toshiaki Ina, Kazuo Kato, Kiyofumi Nitta, Kei Uera, Tomoya Uruga, Hiroki Miura, Tetsuya Shishido, Junya Ohyama, Atsushi Satsuma, Katsutoshi Sato, Akira Yamamoto, Satoshi Hinokuma, Hiroshi Yoshida, Masato Machida, Seiji Yamazoe, Tatsuya Tsukuda, Kentaro Teramura, Tsunehiro Tanaka

Journal of the American Chemical Society Vol. 140 ( 1 ) page： 176 - 184 2018.1

Language：English Publishing type：Research paper (scientific journal)

© 2017 American Chemical Society. The dynamic behavior of Rh species in 1 wt% Rh/Al2O3 catalyst during the three-way catalytic reaction was examined using a micro gas chromatograph, a NOx meter, a quadrupole mass spectrometer, and time-resolved quick X-ray absorption spectroscopy (XAS) measurements at a public beamline for XAS, BL01B1 at SPring-8, operando. The combined data suggest different surface rearrangement behavior, random reduction processes, and autocatalytic oxidation processes of Rh species when the gas is switched from a reductive to an oxidative atmosphere and vice versa. This study demonstrates an implementation of a powerful operando XAS system for heterogeneous catalytic reactions and its importance for understanding the dynamic behavior of active metal species of catalysts.

DOI： 10.1021/jacs.7b07114

Scopus

PubMed

Reductive Conversion of 5-Hydroxymethylfurfural in Aqueous Solutions by Furan Ring Opening and Rearrangement

Ohyama Junya, Satsuma Atsushi

PRODUCTION OF BIOFUELS AND CHEMICALS WITH BIFUNCTIONAL CATALYSTS page： 159-185 2017.12

The Metal-Support Interaction Concerning the Particle Size Effect of Pd/Al2O3 on Methane Combustion

Kazumasa Murata, Yuji Mahara, Junya Ohyama, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 56 ( 50 ) page： 15993 - 15997 2017.12

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The particle size effect of Pd nanoparticles supported on alumina with various crystalline phases on methane combustion was investigated. Pd/, -Al2O3 with weak metal-support interaction showed a volcano-shaped dependence of the catalytic activity on the size of Pd particles, and the catalytic activity of the strongly interacted Pd/-Al2O3 increased with the particle size. Based on a structural analysis of Pd nanoparticles using CO adsorption IR spectroscopy and spherical aberration-corrected scanning/transmission electron microscopy, the dependence of catalytic activity on Pd particle size and the alumina crystalline phase was due to the fraction of step sites on Pd particle surface. The difference in fraction of the step site is derived from the particle shape, which varies not only with Pd particle size but also with the strength of metal-support interaction. Therefore, this interaction perturbs the particle size effect of Pd/Al2O3 for methane combustion.

DOI： 10.1002/anie.201709124

Web of Science

Scopus

In Situ XAFS Study of Dynamic Behavior of Cu Species in MFI-Zeolite under Element Gases of Ammonia Selective Catalytic Reduction Reviewed

Kakuya Ueda, Junya Ohyama, Atsushi Satsuma

CHEMISTRY LETTERS Vol. 46 ( 9 ) page： 1390 - 1392 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

We studied the dynamic redox behavior of Cu species in zeolite matrix under NH3-SCR using in situ XAFS. Cu2+ species were slowly reduced to Cu+ in flowing NH3, and subsequent addition of NO promoted the reduction to Cu+. In the oxidation step, oxygen alone did not fully oxidize Cu+ to Cu2+, but the Cu+ species were completely oxidized to Cu2+ by NO-O-2. The oxidation step was slower than the reduction step, which suggested that the oxidation step (Cu+ -> Cu2+) is the slow step of the NH3-SCR reaction.

DOI： 10.1246/cl.170451

Web of Science

Investigation of Reaction Mechanism of NO-C3H6-CO-O2 Reaction over NiFe2O4 Catalyst

Kakuya Ueda, Junya Ohyama, Atsushi Satsuma

ACS Omega Vol. 2 ( 7 ) page： 3135 - 3143 2017.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

To elucidate the reaction mechanism of NO-C3H6-CO-O2 over NiFe2O4, we investigated the dynamics of the adsorbed and gaseous species during the reaction using operando Fourier transform infrared (FTIR). The NO reduction activity dependent on the C3H6 and CO concentrations suggested that NO is reduced by C3H6 under three-way catalytic conditions. From FTIR measurements and kinetic analysis, it was clarified that the acetate species reacted with NO-O2 to form N2 via NCO, and that the rate-limiting step of NO reduction was the reaction between CH3COO- and NO-O2. The NO reduction mechanism of the three-way catalyst on NiFe2O4 is different to that on platinum-group metal catalysts, on which NO reduction proceeds through N-O cleavage.

DOI： 10.1021/acsomega.7b00165

Web of Science

Scopus

Glucose Isomerization Using Alkali Metal and Alkaline Earth Metal Titanates

Junya Ohyama, Yutong Zhang, Jun Ito, Atsushi Satsuma

CHEMCATCHEM Vol. 9 ( 14 ) page： 2864 - 2868 2017.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Glucose isomerization was performed using various titanate catalysts, which include SrTiO3, BaTiO3, CaTiO3, Na2Ti6O13, K2Ti6O13, and Sr3Ti2O7, prepared using a conventional solid-phase method. Among the titanates, SrTiO3, CaTiO3, and Na2Ti6O13 offered a relatively high fructose yield (32%) with a high selectivity (68-78%). The yields are comparable to yields reported previously using a Sn-modified BEA zeolite, which shows a high efficiency for glucose isomerization as a Lewis acid catalyst. A study of the mechanism of glucose isomerization on a SrTiO3 catalyst surface by using H-1 NMR spectroscopy suggested that the titanates catalyze the isomerization as base catalysts. Thus, the effect of the basicity of the titanates on glucose isomerization was investigated in terms of the base quantity and strength. The analysis was performed by using an acid-base titration method and FTIR spectroscopy with CHCl3 as a probe molecule. It is proposed that glucose isomerization on the titanates depends not only on the base amount but also on the base strength.

DOI： 10.1002/cctc.201700068

Web of Science

Scopus

Hydrogenative ring-rearrangement of biomass derived 5-(hydroxymethyl) furfural to 3-(hydroxymethyl) cyclopentanol using combination catalyst systems of Pt/SiO2 and lanthanoid oxides Reviewed

J. Ohyama, Y. Ohira, A. Satsuma

CATALYSIS SCIENCE & TECHNOLOGY Vol. 7 ( 14 ) page： 2947 - 2953 2017.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Combination catalyst systems composed of Pt/SiO2 and lanthanoid oxides (Pt/SiO2 + LOx) efficiently catalyze the hydrogenative ring-rearrangement of 5-(hydroxymethyl) furfural (HMF) in water to produce 3-(hydroxymethyl) cyclopentanol (HCPO), which can be a unique building block for new materials derived from biomass. We investigated the reason for the efficient hydrogenative ring-rearrangement on Pt/SiO2 + LOx in terms of the acid-base properties of reaction systems, since H+ and Lewis acids can affect the rearrangement of the furan ring. It is indicated that the ring-rearrangement efficiently proceeds under slightly acidic conditions (pH = 5-7) with moderate or a little weak Lewis acidity of lanthanoid oxides.

DOI： 10.1039/c7cy00712d

Web of Science

A Theoretical Insight into Enhanced Catalytic Activity of Au by Multiple Twin Nanoparticles Reviewed

Kyoichi Sawabe, Taiki Koketsu, Junya Ohyama, Atsushi Satsuma

CATALYSTS Vol. 7 ( 6 ) page： 191 2017.6

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI AG

Recently, it has been reported that the morphology of Au nanoparticles (NPs) affects the catalytic activity of CO oxidation; twin crystal NPs show higher activity for CO oxidation than single-crystal NPs. In this study, density functional calculations have been carried out to investigate the morphology effect of Au NPs using CO as a probe molecule. In the case of Au NPs with a size of more than 2 nm, CO adsorption energy on the Au NPs is mainly determined by a coordination number (CN) of adsorption sites. CO binding to a multiple twin NP with a size of about 1 nm is stronger than that on a single-crystal NP with the same size. A simple CN explanation cannot be applied to the enhancement of CO binding to the small multiple twin NP. This enhancement is related to a deformation of the NP structure before and after CO adsorption. It is suggested that the multiple twin NP with a size of less than 1 nm, which shows the deformation upon CO adsorption, contributes to the higher activity for CO oxidation.

DOI： 10.3390/catal7060191

Web of Science

Scopus

Methane combustion over Pd/CoAl2O4/Al2O3 catalysts prepared by galvanic deposition

Yuji Mahara, Takumi Tojo, Kazumasa Murata, Junya Ohyama, Atsushi Satsuma

RSC ADVANCES Vol. 7 ( 55 ) page： 34530 - 34537 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Pd/CoAl2O4/Al2O3 methane combustion catalysts were synthesized using a galvanic deposition (GD) method (PdCoAl-GD). This PdCoAl-GD catalyst showed higher activities and turnover frequencies (TOFs) than conventional Pd/Al2O3. According to X-ray diffraction (XRD), X-ray absorption fine structure (XAFS) and scanning transmission electron microscopy (STEM) measurements, PdCoAl-GD was composed of a CoAl2O4 phase supported on gamma-Al2O3 and dispersed Pd nanoparticles of 2-7 nm in size on CoAl2O4. Operando Pd K-edge XAFS measurements indicated that the Pd in PdCoAl-GD was oxidized to highly active methane combustion PdO species at low temperatures. PdCoAl-GD also showed high activity (light-off tests) when PdO was initially present on the catalysts. Methane temperature-programmed reaction (CH4-TPR) measurements on PdCoAl-GD revealed that PdO was reduced by CH4 at low temperatures. The GD method used herein achieved PdO species that were effective for C-H activation.

DOI： 10.1039/c7ra06150a

Web of Science

Scopus

In situ XAFS study of dynamic behavior of cu species in MFI-Zeolite under element gases of ammonia selective catalytic reduction

Ueda K., Ohyama J., Satsuma A.

Chemistry Letters Vol. 46 ( 9 ) page： 1390 - 1392 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Chemistry Letters

We studied the dynamic redox behavior of Cu species in zeolite matrix under NH3-SCR using in situ XAFS. Cu2+ species were slowly reduced to Cu+ in flowing NH3, and subsequent addition of NO promoted the reduction to Cu+. In the oxidation step, oxygen alone did not fully oxidize Cu+ to Cu2+, but the Cu+ species were completely oxidized to Cu2+ by NOO2. The oxidation step was slower than the reduction step, which suggested that the oxidation step (Cu+ ¼ Cu2+) is the slow step of the NH3-SCR reaction.

DOI： 10.1246/cl.170451

Scopus

Hydrogenative ring-rearrangement of biomass derived 5-(hydroxymethyl)furfural to 3-(hydroxymethyl)cyclopentanol using combination catalyst systems of Pt/SiO<inf>2</inf> and lanthanoid oxides

Ohyama J., Ohira Y., Satsuma A.

Catalysis Science and Technology Vol. 7 ( 14 ) page： 2947 - 2953 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Catalysis Science and Technology

Combination catalyst systems composed of Pt/SiO2 and lanthanoid oxides (Pt/SiO2 + LOx) efficiently catalyze the hydrogenative ring-rearrangement of 5-(hydroxymethyl)furfural (HMF) in water to produce 3-(hydroxymethyl)cyclopentanol (HCPO), which can be a unique building block for new materials derived from biomass. We investigated the reason for the efficient hydrogenative ring-rearrangement on Pt/SiO2 + LOx in terms of the acid-base properties of reaction systems, since H+ and Lewis acids can affect the rearrangement of the furan ring. It is indicated that the ring-rearrangement efficiently proceeds under slightly acidic conditions (pH = 5-7) with moderate or a little weak Lewis acidity of lanthanoid oxides.

DOI： 10.1039/c7cy00712d

Scopus

Investigation of controlling factor for combustion of diesel soot - Effect of oxygen containing functional groups

Saori Hoshi, Daiki Yamashita, Yuji Mahara, Junya Ohyama, Atsushi Satsuma

COMODIA 2017 - 9th International Conference on Modeling and Diagnostics for Advanved Engine Systems 2017

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Japan Society of Mechanical Engineers

DPF (Diesel Particulate Filter) is effective for trapping diesel soot from diesel engines. The trapped diesel soot is removed by combustion above 600°C using excess fuels, which results in reduction of fuel economy. An effective design of DPF is strongly required to improve DPF regeneration efficiency and fuel economy
however, the internal phenomenon of diesel soot combustion on DPF is still not clarified. For an effective design of DPF, in this study, we investigated the effect of diesel soot structure on combustion temperature using real diesel soot. Soot samples were characterized by means of various physicochemical techniques: XPS (X-ray photoelectron spectroscopy), EELS (Electron Energy Loss Spectroscopy), Raman spectroscopy, TEM (transmission electron microscopy), and elemental analysis. TEM images and Raman spectra of real diesel soot showed that the difference in the crystallinity of soot was small. XPS, EELS, and elemental analysis revealed that oxygen content, which is derived from surface functional groups of - COOH, -OH, and - C=O at defect sites, was strongly affected by the engine operating conditions. The ignition temperature of diesel soot was dependent on O/C ratio measured by elemental analysis. With the increase in oxygen content of diesel soot, combustion temperatures of soot became lower. It was concluded that the concentration of oxygen containing functional groups is an essential factor for the control of the ignition temperature of diesel soot.

Scopus

Improved hydrogen oxidation reaction under alkaline conditions by ruthenium -iridium alloyed nanoparticles Reviewed

J. Ohyama, D. Kumada, A. Satsuma

J. Mater. Chem. A Vol. 4 page： 15980-15985 2016.9

NiFe2O4 as an Active Component of Platinum-Group Metal Free Automotive Three-way Catalyst Reviewed

Kakuya Ueda, Cheen Aik Ang, Yoshihiro, Itoh, Junya Ohyama, Atsushi Satsuma

Catal. Sci. Technol. page： in preass 2016.7

Effect of FeOx-Modification of Al2O3 on Its Supported Au Catalyst for Hydrogenation of 5-Hydroxymethylfurfural Reviewed

Junya Ohyama, Yoshinori Hayashi, Kakuya Ueda, Yuta Yamamoto, Shigoe Arai, Atsushi Satsuma

J. Phys. Chem. C page： accpted 2016.6

Formation of Ru Shell on Co/Al2O3 by Galvanic Deposition Method and Its High Catalytic Performance for Three-Way Conversion Reviewed

Junya Ohyama, Hiroyuki Ishikawa, Yuji Mahara, Takumi Nishiyama, Atsushi Satsuma

Bull. Chem. Soc. Jpn 2016.5

Enhanced activity for methane combustion over Pd/Co/Al2O3 catalyst prepared by galvanic deposition method Reviewed

Yuji Mahara, Junya Ohyama, Takumi Tojo, Kazumasa Murata, Hiroyuki Ishikawa, Atsushi Satsuma

Catal. Sci. Tech. page： accepted 2016.5

Ag-M (M: Ni, Co, Cu, Fe) Bimetal Catalysts prepared by Galvanic Deposition Method for CO oxidation Reviewed

Yuji Mahara, Hiroyuki Ishikawa, Junya Ohyama, Kyoichi Sawabe, Atsushi Satsuma

Catal. Today Vol. 265 page： 2-6 2016.1

Atomic-Scale Insight into the Structural Effect of a Supported Au Catalyst Based on a Size-Distribution Analysis Using Cs-STEM and Morphological Image-Processing Reviewed

Junya Ohyama, Akihiko Esaki, Taiki Koketsu, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

J. Catal. Vol. 335 page： 24-35 2016.1

Investigation of Size Effect of Ag Nanoparticles on Oxygen Reduction Reaction Using Ag/Co/C Catalysts Prepared by Galvanic Deposition Method Reviewed

Junya Ohyama, Yui Okata, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

Catal. Lett. Vol. 146 page： 22-27 2015.11

Low temperature combustion over supported Pd catalysts - Strategy for catalyst design Invited Reviewed

Atsushi Satsuma, Kaoru Osaki, Masatoshi Yanagihara, Junya Ohyama, Kenichi Shimizu

Catal. Today Vol. 258 page： 83-89 2015.10

Preparation of TiO2-Supported Twinned Gold Nanoparticles by CO Treatment and Their CO Oxidation Activity Reviewed

Junya Ohyama, Taiki Koketsu, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

Chem. Commun. Vol. 51 page： 15823-15826 2015.10

Effect of Heterogeneous Acid-Base Catalysis on Conversion of 5-Hydroxymethylfurfural into A Cyclopentanone Derivative Reviewed

J. Ohyama, R. Kanao, Y. Ohira, A. Satsuma

Green Chemistry page： article online 2015.9

Automotive Three Way Catalytic Activity of Fe-Ni/Ceria

Atsushi Satsuma, Kakuya Ueda, Yoshihiro Ito, Cheen Aik Ang, Junya Ohyama

Chem. Lett. Vol. 44 ( 5 ) page： 703-705 2015.2

Substrate Specific Heterogeneous Catalysis of CeO2 by Entropic Effects via Multiple Interactions Reviewed

Masazumi Tamura, Kyoichi Sawabe, Keiichi Tomishige, Atsushi Satsuma, Ken-Ichi Shimizu

ACS Catalysis Vol. 5 ( 1 ) page： 20–26 2014.11

Promotion of low-temperature oxidation of CO over Pd supported on titania-coated ceria Reviewed

Atsushi Satsuma, Masatoshi Yanagihara, Kaoru Osaki, Yurina Saeki, Heng Liu, Yuta Yamamoto, Shigeo Arai, Junya Ohyama

RSC Advances Vol. 4 page： 54187-54193 2014.10

6. Effect of preparation method of Co-promoted Pd/alumina for methane combustion Reviewed

Atsushi Satsuma, Takumi Tojo, Kohei Okuda, Yuta Yamamoto, Shigeo Arai, Junya Oyama

Catal. Today Vol. 242 page： 308-314 2014.7

Enhanced CO Oxidation Activity of Ni@Ag Core-Shell Nanoparticles Reviewed

Y. Mahara, H. Ishikawa, J. Ohyama, K. Sawabe, Y. Yamamoto, S. Arai, A. Satsuma

Chem. Lett. Vol. 43 page： 910–912 2014.6

Conversion of 5-Hydroxymethylfurfural to a Cyclopentanone Derivative by Ring Rearrangement over Supported Au Nanoparticles Reviewed

Junya Ohyama,Ryusuke Kanao, Akihiko Esakia, Atsushi Satsuma

Chem. Commun. Vol. 50 page： 5633-5636 2014.5

Density-functional theoretical study on the role of Lewis and Brønsted acid sites on CeO2(110) surfaces for nitrile hydration Reviewed

Vol. 57 page： 1094-1102 2014.5

Statistical Distribution of Single Atoms and Clusters of Supported Au Catalyst Analysed by Global High-Resolution HAADF-STEM Observation with Morphological Image-Processing Operation Reviewed

Yita Yamamoto, Shigeo Arai, Akihiko Esaki, Junya Ohyama, Atsushi Satsuma, Nobuo Tanaka

Microscopy Vol. 63 ( 3 ) page： 209-218 2014.1

Oxygen Reduction Reaction over Silver Particles with Various Morphologies and Surface Chemical States Corresponding Reviewed

Junya Ohyama, Yui Okata, Noriyuki Watabe, Makoto Katagiri, Ayaka Nakamura, Hidekazu Arikawa, Ken-ichi Shimizu, Tatsuya Takeguchi, Wataru Ueda, Atsushi Satsuma

J. Power Sources Vol. 245 page： 998-1004 2013.7

Size Specifically High Activity of Ru Nanoparticles for Hydrogen Oxidation Reaction in Alkaline Electrolyte Reviewed

Junya Ohyama, Takuma Sato, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

J. Am. Chem. Soc. Vol. 135 ( 21 ) page： 8016–8021 2013.4

Heterogeneous Ni Catalysts for N-Alkylation of Amines with Alcohols Reviewed

Ken-Ichi Shimizu, Naomichi Imaiida, Kenichi Kon, Siddiki Hakim, Atsushi Satsuma

ACS Catal. Vol. 3 page： 998-1005 2013.4

CeO2-catalyzed nitrile hydration to amide: reaction mechanism and active site Reviewed

Masazumi Tamura, Atsushi Satsuma, Ken-ichi Shimizu

Catal. Sci. Tech Vol. 3 ( 5 ) page： 1386-1393 2013.2

Activity Controlling Factors for Low-Temperature Oxidation of CO over Supported Pd Catalysts Reviewed

Atsushi Satsuma, Kaoru Osaki, Masatoshi Yanagihara, Junya Ohyama, Kenichi Shimizu

Appl. Catal. B: Environ. Vol. 132-133 page： 511-518 2013.1

Oxidation of CO over Ru/Ceria prepared by Self-dispersion of Ru Metal Powder into Nano-sized Particle Reviewed

Atsushi Satsuma, Masatoshi Yanagihara, Junya Ohyama, and Kenichi Shimizu

Catal. Today Vol. 201 page： 62-67 2012.12

High Performance of Ru Nanoparticles Supported on Carbon for Anode Electrocatalyst of Alkaline Anion Exchange Membrane Fuel Cell Reviewed

Junya Ohyama, Takuma Sato, Atsushi Satsuma

J. Power Sources Vol. 225 page： 311-315 2012.11

Selective Hydrogenation of 2,5-Hydroxymethylfurfural to 2,5-Bishydroxymethylfurfural over Gold Sub-nano cluster Reviewed

Junya Ohyama, Akihiko Esaki, Yuta Yamamoto, Shigeo Arai, Atsushi Satsuma

RSC Advances Vol. 3 page： 1033-1036 2012.11

CeO2-catalyzed Transformations of Nitriles and Amides (Highlight review) Invited Reviewed

Kenichi Shimizu, Masazumi, Tamura, Atsushi Satsuma

Chem. Lett. Vol. 41 page： 1397-1441 2012.11

Surface Oxygen Atom as Cooperative Ligand in Pd Nanoparticles Catalysis for Selective Hydration of Nitriles to Amides in Water: Experimental and Theoretical Studies Reviewed

Ken-Ichi Shimizu, Takahiro Kubo, Atsushi Satsuma, Takashi Kamachi, Kazunari Yoshizawa

ACS Catalysis Vol. 2 page： 2467-2474 2012.11

Heterogeneous nickel catalyst for selective hydration of silanes to silanols Reviewed

Ken-ichi Shimizu, Katsuya Shimura, Naomichi Imaiida, Atsushi Satsuma

J. Mol. Catal. A:Chem. Vol. 365 page： 50-54 2012.10

Volcano-curves for dehydrogenation of 2-propanol and hydrogenation of nitrobenzene by SiO2-supported metal nanoparticles catalysts as described in terms of d-band model Reviewed

Masazumi Tamura, Kon Kenichi, Atsushi Satsuma, Ken-Ichi Shimizu

ACS Catal. Vol. 2 page： 1904-1909 2012.8

Comprehensive IR study on acid/base properties of metal oxides Reviewed

Masazumi Tamura, Ken-ichi Shimizu, Atsushi Satsuma

Appl. Catal. A: General Vol. 433-434 page： 135-145 2012.7

Unique effect of surface area of support on propene combustion over Pd/ceria Reviewed

Atsushi Satsuma, Ryota Sato, Kaoru Osaki, Kenichi Shimizu

Catal. Today Vol. 185 page： 61-65 2012.5

Unique effect of surface area of support on propene combustion over Pd/ceria Reviewed

Atsushi Satsuma, Ryota Sato, Kaoru Osaki, Kenichi Shimizu

Catal. Today Vol. 185 page： 61-65 2012.5

Sulfur promoted Pt/SiO2 catalyzed cross-coupling of anilines and amines Reviewed

Ken-ichi Shimizu, Katsuya Shimura, Naoko Tamagawa, Masazumi Tamura, Atsushi Satsuma

Appl. Catal. A: General Vol. 417-418 page： 37-42 2012.4

Hydration of nitriles to amides in water by SiO2-supported Ag catalysts promoted by adsorbed oxygen atoms Reviewed

Ken-ichi Shimizu, Masamichi Imaiida, Kyoichi Sawabe, Atsushi Satsuma

Appl. Catal. A: General Vol. 421-422 page： 114-120 2012.4

The Average Pd oxidation state in Pd/SiO2 quantified by L3 edge XANES analysis and its effects on catalytic activity for CO oxidation Reviewed

Ken-ichi Shimizu, Yuichi Kamiya, Kaoru Osaki, Hisao Yoshida, Atsushi Satsuma

Catal. Sci. Technol. Vol. 2 page： 767-772 2012.4

Size- and support-dependent selective amine cross-coupling with platinum nanocluster catalysts Reviewed

Ken-ichi Shimizu, Kenichiro Ohshima, Masazumi Tamura, Atsushi Satsuma

Catal. Sci. Technol. Vol. 2 page： 730-738 2012.4

CeO2-catalysed one-pot selective synthesis of esters from nitriles and alcohols Reviewed

Masazumi Tamura, Takuya Tonomura, Ken-ichi Shimizu, Atsushi Satsuma

Green Chem. Vol. 14 page： 984-991 2012.3

Transamidation of amides with amines in solvent-free condition by CeO2 Reviewed

Masazumi Tamura, Takuya Tonomura, Ken-ichi Shimizu, Atsushi Satsuma

Green Chem Vol. 14 page： 717-724 2012.3

Kinetic analysis of reduction process of supported Rh/Al2O3 catalysts by time resolved in-situ UV-vis spectroscopy, Reviewed

Qiang Lin, Ken-ichi Shimizu, Atsushi Satsuma

Appl. Catal. A:Gen Vol. 419-420 page： 142-147 2012.3

Surface Oxygen-Assisted Pd Nanoparticle Catalysis for Selective Oxidation of Silanes to Silanols Reviewed

Ken-ichi Shimizu, Takahiro Kubo, Atsushi Satsuma

Chem. Euro. J. Vol. 18 page： 2226-2229 2012.2

CeO2-catalyzed one-pot selective synthesis of N-alkyl amides from nitriles, amines and water Reviewed

Masazumi Tamura, Takuya Tonomura, Ken-ichi Shimizu, Atsushi Satsuma

Appl. Catal. A: General Vol. 417-418 page： 6-12 2012.2

Electronic effect of Na promotion for selective mono-N-alkylation of aniline with di-iso-propylamine by Pt/SiO2 catalysts Reviewed

Ken-ichi Shimizu, Katsuya Shimizu, Naoko Tamagawa, Masazumi Tamura, Atsushi Satsuma

J. Mol. Catal. A: Chemical. Vol. 353-354 page： 171-177 2012.2

Quantitative determination of average rhodium oxidation state by a simple XANES analysis Reviewed

Ken-ichi Shimizu,Tomonori Oda, Yuichi Kamiya Hisao Yoshida, Atsushi Satsuma

Applied Catalysis B Vol. 111-112 page： 509-514 2011.12

Silver Cluster Catalysts for Green Organic Synthesis Invited Reviewed

Ken-ichi Shimizu and Atsushi Satsuma

Journal of the Japan Petroleum Institute Vol. 54 page： 347-360 2011.12

Direct Synthesis of N-Substituted Anilines from Nitroaromatics and Alcohols under H₂ by Alumina-Supported Silver Cluster Catalyst Reviewed

Kenichi Shimizu, Katsuya Shimura, Masanari Nishimura, Atsushi Satsuma

ChemCatChem Vol. 3 page： 1755-1758 2011.12

Selective cross-coupling of amines by alumina-supported palladium nanocluster catalysts Reviewed

Kenichi Shimizu, Keiichiro Ohsima, Atsushi Satsuma

Green Chem. Vol. 13 page： 3096–3100 2011.11

Silver Cluster-Promoted Heterogeneous Copper Catalyst for N-Alkylation of Amines with Alcohols Reviewed

Kenichi Shimizu, Katsuya Shimura, Masanari Nishimura, Atsushi Satsuma

RSC Advances Vol. 1 page： 1310-1317 2011.11

Efficient and Substrate-Specific Hydration of Nitriles to Amides in Water by CeO₂ Catalyst Reviewed

Masazumi Tamura, Hiroko Wakasugi, Ken-ichi Shimizu, Atsushi Satsuma

Chemistry - A European Journal Vol. 17 page： 11428-11431 2011.9

Sintering-resistant and self-regenerative properties of Ag/SnO₂ catalyst for soot oxidation Reviewed

Ken-ichi Shimizu, Makoto Katagiri, Shigeo Satokawa, Atsushi Satsuma

Appl. Catal. B: Environ. Vol. 108-109 page： 39-46 2011.9

Carbon Oxidation with Ag/Ceria Prepared by Self-dispersion of Ag Powder into Nano-particles Reviewed

Ken-ichi Shimizu, Hiroshi Kawachi, Shin-ichi Komai, Kaname Yoshida, Yukichi Sasaki, and Atsushi Satsuma

Catal. Today Vol. 175 page： 93-99 2011.9

Toward a rational control of solid acid catalysis for green synthesis and biomass conversion Invited Reviewed

Kenichi Shimizu, Atsushi Satsuma

Energy Environ. Sci. Vol. 4 ( 9 ) page： 3140 - 3153 2011.8

Self-Regenerative Silver Nanocluster Catalyst for CO Oxidation Reviewed

Ken-ichi Shimizu, Kyoichi Sawabe, Atsushi Satsuma

ChemCatChem Vol. 3 page： 1290–1293 2011.8

Selective hydrogenation of nitrocyclohexane to cyclohexanone oxime by alumina-supported gold cluster catalysts Reviewed

Ken-ichi Shimizu, Takumi Yamamoto, Yutaka Tai, Atsushi Satsuma

J. Mol. Catal.A:Chem. Vol. 345 page： 54-59 2011.7

Addition of olefins to acetylacetone catalyzed by cooperation of Bronsted acid site of zeolite and gold cluster Reviewed

Ken-ichi Shimizu, Takumi Yamamoto, Yutaka Tai, Kazu Okumura, Atsushi Satsuma

Appl. Catal. A: Gen. Vol. 400 page： 171-175 2011.6

Unique catalytic features of Ag nano-cluster and nano-particles for selective NOx reduction and green chemical reactions Invited Reviewed

Kenichi Shimizu, Kyoichi Sawabe, Atsushi Satsuma

Catal. Sci. Technol. Vol. 1 ( 3 ) page： 331 - 341 2011.2

Effect of Acidity and Pore Diameter of Zeolites on Detection of Base Molecules by Zeolite Thick Film Sensor Reviewed

Atsushi Satsuma, Daojin Yang, Kenichi Shimizu

Microporous and Mesoporous Materials Vol. 141 page： 20-25 2011.2

Effects of Calcination Temperature and Acid-Base Properties on Mixed Potential Ammonia Sensor Modified by Metal Oxides Invited Reviewed

Atsushi Satsuma, Makoto Katagiri, Shiro Kakimoto, Satoshi Sugaya, and Ken-ichi Shimizu

Sensors Vol. 11 page： 2155-2165 2011.2

Density functional theory calculation on the promotion effect of H2 in the selective catalytic reduction of NOx over Ag-MFI zeolite Reviewed

Kyoichi Sawabe, Taisuke Hiro, Ken-ichi Shimizu, Atsushi Satsuma

Catal. Today Vol. 153 ( 3-4 ) page： 90-94 2010.9

Hydrogenation of pyrene using Pd catalysts supported on tungstated metal oxides Reviewed

Qiang Lin, Ken-ichi Shimizu, Atsushi Satsuma

Appl. Catal. A:Gen. Vol. 387 page： 166–172 2010.9

Design of active centers for bisphenol-A synthesis by organic-inorganic dual modification of heteropolyacid Reviewed

Kenichi Shimizu, Soichiro Kontani, Soichiro Yamada, Go Takahashi, Takahito Nihisyama, Atsushi Satsuma

Appl. Catal. A:Gen Vol. 380 page： 33-39 2010.5

Effect of Pt and Ba content on NOx Storage and Reduction over Pt/Ba/Al2O3 Reviewed

Yoshinori Saito, Kenichi Shimizu, Takeshi Nobukawa, and Atsushi Satsuma

Top. Catal. Vol. 53 page： 584-590 2010.5

Study of active sites and mechanism for soot oxidation by silver-loaded ceria catalyst Reviewed

Ken-ichi Shimizu, Hiroshi Kawachi, and Atsushi Satsuma

Appl. Catal.B Vol. 96 page： 169-175 2010.4

Depletion of CO oxidation activity of supported Au catalysts prepared from thiol-capped Au nanoparticles by sulfates formed at Au–titania boundaries: Effects of heat treatment conditions on catalytic activity Reviewed

Yutaka Tai, Wataru Yamaguchi, Masahisa Okada, Fumihiko Ohashi, Ken-ichi Shimizu, Atsushi Satsuma, Koji Tajiri, Hiroyuki Kageyama

J. Catal. Vol. 270 page： 234-241 2010.3

Size- and support-dependent silver cluster catalysis for chemoselective hydrogenation of nitroaromatics Reviewed

Ken-ichi Shimizu, Yuji Miyamoto, and Atsushi Satsuma

J. Catal. Vol. 270 page： 86-94 2010.2

Silica-Supported Silver Nanoparticles with Surface Oxygen Species as a Reusable Catalyst for Alkylation of Arenes Reviewed

Ken-ichi Shimizu, Yuji Miyamoto, Atsushi Satsuma

Chem. Cat. Chem. Vol. 21 ( (1) ) page： 84-91 2010.1

γ-Alumina Supported Silver Cluster for N-Benzylation of Anilines with Alcohols Reviewed

Ken-ichi Shimizu, Masanari Nishimura, Atsushi Satsuma

Chem. Cat. Chem. Vol. 1 page： 497-503 2009.12

* Effects of Brønsted and Lewis acidities on activity and selectivity of heteropolyacid-based catalysts for hydrolysis of cellobiose and cellulose Reviewed

Ken-ichi Shimizu, Hirotake Furukawa, Nobusuke Kobayashi, Yoshinori Itaya, and Atsushi Satsuma

Green Chem. Vol. 11 page： 1627-1632 2009.11

* Chemoselective Hydrogenation of Nitroaromatics by Supported Gold Catalysts: Mechanistic Reasons of Size- and Support-Dependent Activity and Selectivity Reviewed

Ken-ichi Shimizu, Yuji Miyamoto, Tadahiro Kawasaki, Takayoshi Tanji, Yutaka Tai, Atsushi Satsuma

Vol. 113 page： 17803-17810 2009.10

Direct Dehydrogenative Amide Synthesis from Alcohols and Amines Catalyzed by γ-Alumina Supported Silver Cluster Reviewed

Ken-ichi Shimizu, Keiichiro Ohshima, Atsushi Satsuma

Chemistry - A European Journal Vol. 15 page： 9977-9980 2009.10

Doped-vanadium oxides as sensing materials for high temperature operative selective ammonia gas sensors Reviewed

Ken-ichi Shimizu, Isao Chinzei, Hiroyuki Nishiyama, Shiro Kakimoto, Satoshi Sugaya, Wataru Matsutani, Atsushi Satsuma

Sensors and Actuators B Vol. 141 page： 410-416 2009.8

Enhanced production of hydroxymethylfurfural from fructose with solid acid catalysts by simple water removal methods Reviewed

Ken-ichi Shimizu, Rie Uozumi, Atsushi Satsuma

Catal. Commun. Vol. 10 page： 1849-1853 2009.8

Redox Property of Tungstated- Zirconia Analyzed by Time Resolved in-situ UV-visible Spectroscopy Reviewed

Qiang Lin, Ken-ichi Shimizu, Atsushi Satsuma

Appl. Catal. A:Gen. Vol. 365 ( 1 ) page： 55-61 2009.7

* Direct C-C Cross-coupling Reaction from Secondary and Primary Alcohols Catalyzed by gamma-Alumina Supported Silver Subnano-Cluster Reviewed

K. Shimizu, R. Sato, A. Satsuma,

Angew. Chem. Int. Ed. Vol. 48 page： 3982-3986 2009.5

* Oxidant-Free Dehydrogenation of Alcohols Heterogeneously Catalyzed by Cooperation of Silver Clusters and Acid-Base Sites on Alumina Reviewed

K. Shimizu, K. Suguno, K. Sawabe, A. Satsuma,

Chem. Euro. J. Vol. 15 page： 2341-2351 2009.2

Effect of Supports on Formation and Reduction Rate of Stored Nitrates on NSR Catalysts as Investigated by in-situ FT/IR Reviewed

K. Shimizu, Y. Saito, T. Nobukawa, N. Miyoshi, A. Satsuma

Catal. Today Vol. 139 page： 24-28 2008.10

Hydrogen sensor based on WO3 subnano-clusters and Pt co-loaded on ZrO2 Reviewed

KSens. Actuators. B Vol. 134 page： 618-624 2008.9

Polyvalent-metal salts of heteropolyacid as catalyst for Friedel-Crafts alkylation reactions Reviewed

Ken-ichi Shimizu, Kenjiro Niimi and Atsushi Satsuma

Appl. Catal. A Vol. 349 ( 1-2 ) page： 1-5 2008.9

Selective Oxidation of n-Butane over Fe-promoted Vanadyl Pyrophosphate Prepared from Modification of Nano-sized Interlayer of Lamellar Vanadyl Benzylphosphate Reviewed

Kannan Srinivasan, Hironaka Kanbe, Takuya Ohkura, Shin-ichi, Komai, Yuichi Kamiya, Tadashi Hattori, and Atsushi Satsuma

Res. Chem. Intermd Vol. 34 ( 5-7 ) page： 455-465 2008.6

Characterization of Lewis acidity of cation-exchanged montmorillonite K-10 clay as effective heterogeneous catalyst for acetylation of alcohol Reviewed

Ken-ichi Shimizu, Tomoya Higuchi, Emi Takasugi, Tsuyoshi Hatamachi, Tatsuya Kodama and Atsushi Satsuma

Journal of Molecular Catalysis A: Chemical Vol. 284 page： 89-96 2008.4

Impedancemetric gas sensor based on Pt and WO3 co-loaded TiO2 and ZrO2 as total NOx sensing materials, Reviewed

Ken-ichi Shimizu, Kohichi Kashiwagi, Hiroyuki Nishiyama, Shiro Kakimoto, Satoshi Sugaya, Hitoshi Yokoi and Atsushi Satsuma

Sensors and Actuators B: Chemical Vol. 130 page： 707-712 2008.4

Control of Nano-sized Interlayer Space of Lamellar Vanadyl Benzylphosphate Reviewed

Atsushi Satsuma, Hironaka Kanbe, Kannan Srinivansan, Shin-ich Komai, Yuichi Kamiya, and Tadashi Hattori

Micropor. Mesopor. Mater Vol. 110 ( 2-3 ) page： 528-533 2008.3

Polyvalent-metal salts of heteropolyacid as efficient heterogeneous catalysts for Friedel-Crafts acylation of arenes with carboxylic acids Reviewed

Ken-ichi Shimizu, Kenjiro Niimi and Atsushi Satsuma

Catal. Commun. Vol. 9 ( 6 ) page： 980-983 2008.2

Dicopper(II)-Dioxygen Complexes in Y Zeolite for Selective Catalytic Oxidation of Cyclohexane under Photoirradiation Reviewed

Ken-ichi Shimizu, Yoshiaki Murata, and Atsushi Satsuma

Atsushi Satsuma, J. Phys. Chem. C Vol. 111 page： 19043 - 19051 2007.12

Involvement of NCO Species in Promotion Effect of Water Vapor on Propane-SCR over Co-MFI Zeolite Reviewed

Akira Shichi, Tadashi Hattori and Atsushi Satsuma

Appl. Catal. B Vol. 77 page： 92-99 2007.11

Hydrogen Assisted urea-SCR and NH3-SCR with silver-alumina as highly SO2-torelant de-NOx catalysis Reviewed

Ken-ichi Shimizu and Atsushi Satsuma

Appl. Catal. B Vol. 77 page： 202-205 2007.11

Effect of Modified-Alumina Supports on Propane-Hydrogen-SCR over Ag/Alumina Reviewed

K. Shimizu, M. Hashimoto, J. Shibata, T. Hattori, and A. Satsuma

Catal. Today Vol. 126 page： 266-271 2007.8

Ammonia Sensing Mechanism of Tungstated-Zirconia Thick Film Sensor Reviewed

Atsushi Satsuma, Ken-ichi Shimizu, Koichi Kashiwagi, Tadanori Endo, Hiroyuki Nishiyama, Shiro Kakimoto, Satoshi Sugaya, Hitoshi Yokoi

J. Phys. Chem. C Vol. 111 page： 12080-12085 2007.8

Polytungstate Clusters on Zirconia as a Sensing Material for a Selective Ammonia Gas Sensor Reviewed

Atsushi Satsuma, Ken-ichi Shimizu, Tadashi Hattori, Hiroyuki Nishiyama, Shiro Kakimoto, Satoshi Sugaya, Hitoshi Yokoi

Sens. Actuators, B Vol. 123 page： 757-762 2007.5

Reaction Mechanism of H2-Promoted Selective Catalytic Reduction of NO with C3H8 over Ag-MFI Zeolites Reviewed

Ken-ichi Shimizu, Kenji Sugino, Kazuo Kato, Shigeru Yokota, Kazu Okumura, and Atsushi Satsuma

J. Phys. Chem. C Vol. 111 page： 6481-6487 2007.4

Reaction Mechanism of H2-Promoted Selective Catalytic Reduction of NO with NH3 over Ag/Al2O3 Reviewed

Ken-ichi Shimizu, Atsushi Satsuma

J. Phys. Chem. C. Vol. 111 page： 2259-2264 2007.2

Mechanism of Adsorptive Removal of tert-Butanethiol under Ambient Conditions with Silver Nitrate Supported on Silica and Silica-Alumina Reviewed

Ken-ichi Shimizu, Shin-ichi Komai, Toshinori Kojima, Shigeo Satokawa, and Atsushi Satsuma

J. Phys. Chem. C. Vol. 111 page： 3480-3485 2007.2

Effects of hydrogen and oxygenated hydrocarbons on the activity and SO2-tolerance of Ag/Al2O3 for selective reduction of NO Reviewed

Ken-ichi Shimizu, Masao Tsuzuki, Atsushi Satsuma

Appl. Catal. B Vol. 71 page： 80-84 2007.1

Reactive Activation of O2 with H2 Reduced Silver Clusters a Key Step in the H2-Promoted Selective Catalytic Reduction of NO with C3H8 over Ag/Al2O3 Reviewed

Ken-ichi Shimizu, Masao Tsuzuki, Kazuo Kato, Shigeru Yokota, Kazu Okumura, Atsushi Satsuma

J. Phys. Chem. C Vol. 111 page： 950-959 2007.1

Language：English Publishing type：Research paper (scientific journal)

The mechanistic cause of the dramatic activity improvement of alumina-supported silver (Ag/Al2O3)byH2 addition for the selective catalytic reduction of NO with propane (C3H8-SCR) was investigated by catalytic and spectroscopic studies. In situ UV-vis, in situ EXAFS, IR, and microcalorimetric experiments show that
H2 reduction of Ag+ ions on Ag/Al2O3 at 573 K yields protons on alumina and partially reduced Agn clusters, which are subsequently aggregated to larger Ag clusters. During H2 + O2 and H2-assisted C3H8-SCR reactions, Ag+ ions and Agn .+ coexist. Reoxidation with O2 results in the redispersion of the cluster to Ag+ ion, accompanying a reaction of protons. The relationship between cluster size, redox properties, and catalytic activity is examined using Ag/Al2O3 of different Ag loadings. The steady-state NO reduction rate correlates fairly well with the amount of Agn .+ during the H2-assisted C3H8-SCR reaction. It is shown that Agn .+ is the active species, whereas monomeric Ag+ ion and metallic Ag particles are inactive. With Ag loading, the Ag+ reduction rate increases and the rate of cluster reoxidation decreases. A balance between the rate of reduction and reoxidation of Ag species is an important factor that controls the size and oxidation state of the Ag species and consequently the catalytic activity of Ag/Al2O3. ESR has provided evidence, for the first time, for the in situ generation of superoxide ions in H2 + O2 and H2-assisted C3H8-SCR reactions. The comprehensive reason for the hydrogen effect in HC-SCR is discussed, focusing on the role of the cluster and protons on the reductive O2 activation to superoxide ion.

Mechanistic Study on Adsorptive Removal of tert-Butanethiol on Ag-Y Zeolite under Ambient Conditions Reviewed

Ken-ichi Shimizu, Nobumitsu Kobayashi, Atsushi Satsuma, Tohinori Kojima, and Sigeo Satokawa

J. Phys. Chem. B Vol. 110 page： 22570-22576 2006.11

Preparation of V2O5/TiO2 catalyst for NH3-SCR: Controlling factor of TiO2 support for highly active catalyst Reviewed

A. Satsuma, N. Furuta, T. Ogiso, M. Inoue, H. Kominami, K. Kagawa, and T. Hattori

Stud. Surf. Sci. Catal. Vol. 162 page： 785-792 2006.9

Contributions of three types of Ga sites in propane aromatization over Ga2O3/Ga-MOR catalysts Reviewed

, A. Satsuma, A. Gon-no, K. Nishi, S. Komai, and T. Hattori

Stud. Surf. Sci. Catal. Vol. 159 page： 257-260 2006.6

Selective Catalytic Reduction of NO over Supported Silver Catalysts - Practical and Mechanistic Aspects Invited Reviewed

Ken-ichi Shimizu and Atsushi Satsuma

Phys. Chem. Chem. Phys. Vol. 8 page： 2677 – 2695 2006.6

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Selective catalytic reduction of NO by hydrocarbons (HC-SCR) is one of the promising technologies for removal of NO in exhausts containing excess oxygen, such as diesel and lean burn gasoline engines. Supported Ag catalysts, especially Ag/Al2O3, are thought to be the promising candidates for use in diesel exhausts, as con.rmed by several reports on engine bench tests. The HC-SCR performance of supported Ag catalysts is very sensitive to the reaction conditions, especially the type of hydrocarbons and the addition of H2. The control of reaction conditions would be key for practical use. The current research of supported Ag catalysts is reviewed from the viewpoints of practical use and the reaction mechanism, i.e., the reaction scheme, the role of surface adsorbed species, and the structure of active Ag species.

Effect of hydrogen addition on SO2-tolerance of silver-alumina for SCR of NO with propane Reviewed

Ken-ichi Shimizu, Takaaki Higashimata, Masao Tsuzuki, Atsushi Satsuma

J. Catal. Vol. 239 page： 117-124 2006.3

Kinetic and in situ IR studies on SCR of NO with propane by silver-alumina catalyst: Role of H2 on O2 activation and retarding of nitrate-poisoning Reviewed

Ken-ichi Shimizu, Junji Shibata, Atsushi Satsuma

J. Catal. Vol. 239 page： 402-409 2006.3

Photoactive sites on pure silica materials for nonoxidative direct methane, coupling Reviewed

Leny Yuliati, Masanoti Tsubota, Atsushi Satsuma, Hideaki Itoh, Hisao Yoshida

J.Catal. Vol. 238 page： 214-220 2006.1

Involvement of Active Sites of Promoted Vanadyl Pyrophosphate in Selective Oxidation of Propane Reviewed

, Shinji Ieda, Satit Phiyanalinmat, Shin-ichi Komai, Tadashi Hattori, Atsushi Satsuma

J. Catal. Vol. 236 page： 304-312 2005.12

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

Involvement of active sites in the selective oxidation of propane was investigated using (VO)2P2O7 catalysts promoted by Sb, Ti, Zr, Hf, Cu, and Ce. Based on X-ray diffraction patterns, infrared spectra, and Raman spectra, the formation of a (VO)2P2O7 phase was con.rmed for all of the promoted catalysts; no other phases were detected. After the addition of Sb, Ti, and Zr, the selectivity to acrylic acid increased, whereas Cu-, Ce-, and Hf-promoted catalysts showed lower selectivity than pure (VO)2P2O7. The effect of promoters on the activity and selectivity for the propane oxidation was investigated on the basis of the nature of surface active sites. The surface V=O species, evaluated by the nitric oxide.ammonia rectangular pulse technique, decreased with the addition of the promoters. A proportional correlation between the number of surface V=O species and reaction rate of propane clari.ed that the surface V=O species is the controlling factor for the catalytic activity of propane oxidation. In the case of Sb-, Ti-, and Zr-promoted catalysts, the selectivity to acrylic acid increased signi.cantly. The selectivity was compared with the number and strength of Bronsted and Lewis acid sites estimated from dimethylpyridine temperature-programmed desorption. A good correlation was observed between the selectivity to acrylic acid and the surface concentration of Lewis acid sites. It was experimentally demonstrated that Lewis acid sites represent the key factor in selective oxidation.

Determination of Metal Dispersion of Pt/CeO2 Catalyst by CO-pulse Method Reviewed

Shinichi Komai, Yoshiteru Yazawa, Atsushi Satsuma, Tadashi Hattori

J. Jpn. Petro. Inst. Vol. 48 ( 3 ) page： 173-177 2005.5

Acidic properties of sulfonic acid-functionalized FSM-16 mesoporoussilic and its catalytic efficiency for acetalization of carbonyl compounds Reviewed

Ken-ichi Shimizu, Eidai Hayashi, Tsuyoshi Hatamachi, Tatsuya Kodama,Tomoya Higuchi, Atsushi Satsuma, Yoshie Kitayama

Journal of Catalysis Vol. 231 page： 131-138 2005.4

Direct loading of fine particles of Pd on activated carbon in aqueous solution and NO conversion Reviewed

Tomoyuki Okuni, Yasuhiro Sahashi, Atsushi Satsuma, Hidetaka Konno, and Michio Inagaki

TANSO Vol. 217 page： 95-98 2005.4

Acidic properties of sulfonic acid-functionalized FSM-16 mesoporoussilic and its catalytic efficiency for acetalization of carbonyl compounds Reviewed

Ken-ichi Shimizu, Eidai Hayashi, Tsuyoshi Hatamachi, Tatsuya Kodama,Tomoya Higuchi, Atsushi Satsuma, Yoshie Kitayama

Vol. 231 page： 131-138 2005.4

Stability of Pd(II) Ion in Side Pocket of Mordenite under Hydrothermal Conditions Reviewed

Atsushi Satsuma, Yasuhiro Sahashi, Junji Shibata, Koji Nishi, Shigeo Satokawa, Keiji Itabashi, Shin-ichi Komai, Hisao Yoshida, and Tadashi Hattori

Micro. Meso. Mater Vol. 81 page： 135-138 2005.3

Factors controlling activity and selectivity for SCR of NO by hydrogen over supported Pt catalysts

Junji Shibata, Masanori Hashimoto, Ken-ichi Shimizu, Hisao Yoshida, Tadashi Hattori and Atsushi Satsuma

Vol. 108 page： 18327-18335 2004.10

Ag Cluster as Active Species for SCR of NO by propane in the Presence of Hydrogen over Ag-MFI Reviewed

Junji Shibata, Yuu Takada, Akira Shichi, Sigeru Satokawa, Atsushi Satsuma, Tadashi Hattori

J. Catal. Vol. 222 page： 368-376 2004

Influence of zeolite support on activity enhancement by addition of hydrogen for SCR of NO by propane over Ag-zeolites Reviewed

Junji Shibata, Yuu Takada, Akira Shichi, Shigeo Satokawa, Atsushi Satsuma, Tadashi Hattori

Appl. Catal. B Vol. 54 ( 3 ) page： 137-144 2004

Application of Neural Network to Estimation of Catalyst Deactivation in Methanol Conversion Reviewed

S. Kito, A. Satsuma, T. Ishikura, M. Niwa, Y. Murakami, and T. Hattori

Catal. Today Vol. 97 page： 41-47 2004

Structure of active Ag clusters in Ag-zeolites for SCR of NO by propane in the presence of hydrogen Reviewed

Junji Shibata, Ken-ichi Shimizu, Yuu Takada, Akira Shichi, Hisao Yoshida, Shigeo Satokawa, Atsushi Satsuma, and Tadashi Hattori

J. Catal. Vol. 227 page： 367-374 2004

Direct observation of polytungstate cluster and monolayer tungstate on zirconium oxide by high-resolution TEM Reviewed

Atsushi Satsuma, Hitoshi Yokoi, Hiroyuki Nishiyama, Shiro Kakimoto, Satoshi Sugaya, Takafumi Oshima, Tadashi Hattori

Chem. Lett Vol. 33 page： 1250-1251 2004

Adsorption-controlled Diffusion in Catalytic Reduction of NO with Hydrocarbons over Zeolite Catalysts Reviewed

Akira Shichi, Atsushi Satsuma, and Tadashi Hattori

Catalysis Today Vol. 93-95 page： 777-781 2004

Drastic Enhancement of SCR of NO over Ir Catalyst through Formation of Metallic Iridium on Na-zeolite Reviewed

Junji Shibata, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Chem. Lett. Vol. 33 ( 7 ) page： 800-801 2004

Involvement of solid acid on Al- and Ga-doped porous silica in the Diels-Alder reaction Reviewed

Atsushi Satsuma, Yoshihide Segawa, Hisao Yoshida, and Tadashi Hattori

Appl. Catal. A Vol. 264 ( 2 ) page： 229-236 2004

Enhancing the low temperature activity by adding H2 over Ag/Al2O3 catalyst for the selective reduction of NO by light hydrocarbons under lean-exhaust conditions Reviewed

Shigeo Satokawa, Junji Shibata, Ken-ichi Shimizu, Atsushi Satsuma, and Tadashi Hattori

Appl. Catal. B Vol. 42 page： 179-186 2003

参照触媒を用いる触媒調製の標準化

松本英之, 岡本康昭, 薩摩　篤, 上野晃史, 片田直伸, 松橋博美, 丹羽　幹

触媒 Vol. 45 page： 388-394 2003

UV-visibleスペクトルによる固体触媒表面のin-situ観察 Invited

薩摩篤, 柴田順二, 服部忠

Jasco report Vol. 45 ( 1 ) page： 5-9 2003

In-situ FT/IR Study of Selective Catalytic Reduction of NO over Alumina-based Catalysts Invited

Atsushi Satsuma, Ken-ichi Shimizu

Progress in Energy and Combustion Science Vol. 29 page： 71-84 2003

Zeolite Micropore as Unique Reaction Field for the Selective Catalytic Reduction of NO by Hydrocarbons Invited

Atsushi Satsuma, Akira Shichi, Tadashi Hattori

CATTECH Vol. 7 ( 2 ) page： 6-14 2003

Active Ag species in MFI Zeolite for Direct Methane Conversion in the light and dark Reviewed

H. Yoshida, T. Hamajima, Y. Kato, J. Shibata, A. Satsuma, T. Hattori

Res. Chem. Intermed. Vol. 29 page： 897-910 2003

Selective oxidation of n-butane over iron doped vanadyl pyrophosphate prepared by- intercalation of iron acetylacetonato complex to lamellar vanadyl n-hexylphosphate Reviewed

Yuichi Kamiya, Yuki Kijima, Takuya Ohkura, Atsushi Satsuma, and Tadashi Hattori

Appl. Catal. A Vol. 253 page： 1-13 2003

Support effect of silica on photocatalytic degradation of dibutyl phthalate by TiO2 nanoparticles in water containing chloride anion Reviewed

H. Yoshida, J. Nishimoto, Y. Miyashita, C. Ooka, S. Komai, A. Satsuma, T. Hattori

Chem. Lett. Vol. 2003 ( 32 ) page： 1030-1031 2003

Effect of Active Metal-Addition on Oxidative Coupling of Phenol as a Possible Key Step of Dioxin Formation over de NOx-Related Catalysts Reviewed

Shin'ichi Komai, Atsushi Satsuma, Katsuhiro Tokura and Tadashi Hattori

Organohalogen Compounds Vol. 63 page： 187-190 2003

Nitrous oxide free pathway for selective reduction of NO by hydrogen over supported Pt catalysts Reviewed

Atsushi Satsuma, Masanori Hashimoto, Junji Shibata, Hisao Yoshida, and Tadashi Hattori

Chem. Commun. Vol. 2003 ( 14 ) page： 1698 - 1699 2003

Promotion effect of hydrogen on surface steps in SCR of NO by propane over alumina-based silver catalyst as examined by transient FT-IR Reviewed

Junji Shibata, Ken-ichi Shimizu, Shigeo Satokawa, Atsushi Satsuma, and Tadashi Hattori

Phys. Chem. Chem. Phys. Vol. 5 page： 2154-2160 2003

In-situ UV-visible Spectroscopic Study for Dynamic Analysis of Silver Catalyst Reviewed

Atsushi Satsuma, Junji Shibata, Akio Wada, Yoshio Shinozaki, Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 145 page： 239-242 2003

The Role of Bronsted and Lewis Acids Sites of Vanadyl Pyrophosphate Measured by Dimethylpyridine-temperature Pogrammed Desorption in the Slective Oxidation of Butane Reviewed

Yuichi Kamiya, Hiroyuki Nishiyama, Miki Yashiro, Atsushi Satsuma, and Tadashi Hattori

J. Jpn. Petro. Inst. Vol. 46 ( 1 ) page： 62-68 2003

Preparation and Characterization of Lamellar Vanadyl Alkylphosphates as Catalyst Precursors for the Selective Oxidation of Butane Reviewed

Yuichi Kamiya, Eiichiro Nishikawa Atsushi Satsuma, and Toshio Okuhara

Bull. Chem. Soc. Jpn. Vol. 76 ( 4 ) page： 837-846 2003

Structure and Catalytic Properties of Ga-MFI in Propane Aromatization Reviewed

K. Nishi, S. Komai, K. Inagaki, A. Satsuma, and T. Hattori

Appl. Catal. A:General Vol. 223 ( 1-2 ) page： 187-193 2002

Highly porous vanadium phosphorus oxides derived from vanadyl n-butylphosphate Reviewed

Yuichi Kamiya, E. Nishikawa, Takuya Ohkura, Atsushi Satsuma and Tadashi Hattori

Microporous and Mesoporous Materials Vol. 54 page： 277-283 2002

The support effect on propane combustion over platinum catalyst: control of the oxidation-resistance of platinum by the acid strength of support materials Reviewed

Yoshiteru Yazawa, Nobuyuki Takagi, Hisao Yoshida, Shin-ichi Komai, Atsushi Satsuma and Tadashi Hattori

Appl. Catal. A:General Vol. 233 ( 1-2 ) page： 103-112 2002

Studies on the preparation of supported metal oxide catalysts using JRC-reference catalysts II. Vanadia-titania catalysts: Effect of starting solution and phase of titania

Atsushi Satsuma, Sakae Takenaka, Tsunehiro Tanaka, Sigeru Nojima, Yoshiya Kera and Hisashi Miyata

Appl. Catal. A:General Vol. 232 page： 93-106 2002

Influence of Hydrocarbon Structure on Selective Catalytic Reduction of NO over Cu-Al2O3 Reviewed

Junji Shibata, Ken-ichi, Shimizu, Atsushi Satsuma, and Tadashi Hattori

Appl. Catal. B Vol. 37 ( 3 ) page： 197-204 2002

Promoting Effect of Water Vapor on the Catalytic Activity of Cobalt-exchanged MFI Zeolite for the Selective Reduction of NO by C3H8 Reviewed

Akira Shichi, Atsushi Satsuma, and Tadashi Hattori

Chem. Lett. Vol. 2001 page： 44 2001

Kinetic study of support effect in the propane combustion over platinum catalyst Reviewed

Catal. Lett. Vol. 72 ( 3-4 ) page： 157-160 2001

Synthesis of novel layered vanadyl alkylphosphates using various alcohols Reviewed

Yuichi Kamiya, Eiichiro Nishikawa, Atsushi Satsuma, Noritaka Mizuno and Toshio Okuhara

Journal of The Japan Petroleum Institute Vol. 44 ( 4 ) page： 265-266 2001

Quantification of Aluminium Coordinations in Alumina and Silica-alumina by Al K-edge XANES Reviewed

Y. Kato, K. Shimizu, N. Matsushita, T. Yoshida, H. Yoshida, A. Satsuma and T. Hattori

Phys. Chem. Chem. Phys. Vol. 3 page： 1925 2001

Influence of geometry-limited diffusion on the selective catalytic reduction of NO by hydrocarbons over Cu-exchanged zeolite Reviewed

Akira Shichi, Atsushi Satsuma, Tadashi Hattori

Appl. Catal. B: Environmental Vol. 30 ( 1-2 ) page： 25 2001

Effect of Carbon Number in Hydrocarbon Reduction on the Selective Reduction of NO over Cation-exchanged MFI Zeolites

Akira Shichi, Yuriko Kawamura, Atsushi Satsuma and Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 135 page： 30-O-03 2001

Metal oxide catalysts for selective reduction of NOx by hydrocarbons: toward molecular basis for catalyst design Invited Reviewed

Ken-ichi Shimizu, Atsushi Satsuma and Tadashi Hattori

Catalysis Survey from Japan Vol. 4 ( 2 ) page： 115-123 2001

Photoinduced non-oxidative coupling of methane over H-zeolite around room temperature Reviewed

K. Kato, H. Yoshida, A. Satsuma, T. Hattori

Micro. Meso. Mater. Vol. 51 ( 3 ) page： 223-231 2001

Insertion of iron-complex to lamellar vanadyl benzylphosphate for preparation of well-defined catalyst Reviewed

A. Satsuma, Y. Kijima, S. Komai, Y. Kamiya, E. Nishikawa, T. Hatttori

Catal. Today Vol. 71 ( 1-2 ) page： 161-167 2001

Effect of Oxygen in Decomposition of Nitrous Oxide over Various Metal Oxide Catalysts Reviewed

Atsushi Satsuma, Hajime Maeshima, Kiyoshi Watanabe, and Tadashi Hattori

Energy Conversions and Management Vol. 42 page： 1997-2003 2001

Oxidative Coupling of Phenol: A Possible Key Step of Dioxin Formation on deNOx Catalyst Reviewed

Sin'ichi Komai, Atsushi Satsuma, Katsuhiro Tokura and Tadashi Hattori

Organohalogen Compounds Vol. 50 page： 407-410 2001

Catalytic Sites of Mesoporous Silica in Degradation of Polyethylene Reviewed

Atsushi Satsuma, Takashi Ebigase, Yoshitaka Inaki, Hisao Yoshida, Satoshi Kobayashi, Md. Azhar Uddin, Yusaku Sakata, Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 135 page： 24-P-25 2001

Influence of hydrocarbon molecular size on the selective catalytic reduction of NO by hydrocarbons over Cu-MFI zeolite Reviewed

Akira Shichi, Atsushi Satsuma, Tadashi Hattori

Appl. Catal. A Vol. 207 ( 1-2 ) page： 315 2001

Effect of Pore-diffusion on Catalytic Reduction of NO over Co- and Cu-mordenites Reviewed

Akira Shichi, Atsushi Satsuma, Shin-ichi Komai, and Tadashi Hattori

J. Chem. Eng. Jpn. Vol. 34 ( 2 ) page： 102 2001

Effective Diffusivities of Lighter Hydrocarbons in Cu- and Co- MFI Type Zeolite Catalysts Reviewed

Takao Masuda, Yoshihito Okubo, Kenji Hashimoto, Akira Shichi, Atsushi Satsuma, Tadashi Hattori, and Y. Kiyozumi

Chem. Eng. Sci. Vol. 56 page： 889 2001

Involvement of Redox Sites in Propane Ammoxidation on V-Sb-oxide Catalyst Reviewed

Satit Phiyanalinmat, Miki Yashiro, Atsushi Satsuma, and Tadashi Hattori

Sekiyu Gakkaishi Vol. 44 ( 2 ) page： 140 2001

Crystal field effect on the chemical shift in XANES spectra of Cu(II) compounds Reviewed

Ken-ichi Shimizu, Hajime Maeshima, Hisao Yoshida, Atsushi Satsuma, Tadashi Hattori

Phys. Chem. Chem. Phys. Vol. 3 page： 862 2001

Mechanistic causes of hydrocarbon effect on the activity of Ag-Al2O3 catalyst for selective reduction NO Reviewed

Ken-ichi Shimizu, Junji Shibata, Atsushi Satsuma and Tadashi Hattori

Phys. Chem. Chem. Phys. Vol. 3 page： 880 2001

Silver-alumina catalysts for selective reduction of NO by higher hydrocarbons: structure of active sites and reaction mechanism Reviewed

Ken-ichi Shimizu, Junji Shibata, Hisao Yoshida, Atsushi Satsuma, Tadashi Hattori

Appl. Catal. B: Environmental Vol. 30 ( 1-2 ) page： 151 2001

Language：English Publishing type：Research paper (scientific journal)

Silver-alumina catalysts prepared by sol.gel method (Ag-Al2O3) and impregnation method (Ag/Al2O3) were studied for the selective catalytic reduction (SCR) of NO by higher alkanes (n-hexane and n-octane). UV.VIS and Ag K-edge XAFS results established the structure of the catalysts; below 2 wt.%, highly dispersed Ag+ ions are predominant Ag species, while at higher Ag loading, Agn clusters are predominant. A relationship between the structure of Ag species and their catalytic function for SCR by n-octane was clari.ed. Ag+ ions are responsible for the selective reduction of NO to N2, while the Agn clusters are responsible for the hydrocarbon combustion and N2O formation. The mechanism of SCR by n-hexane on Ag-Al2O3, which mainly consists of Ag+ ions, were investigated by in situ FTIR spectroscopy. During NO + n-hexane + O2 reaction, the acetate produced via the partial oxidation of n-hexane and the nitrates produced via the oxidation of NO were main adspecies in the steady-state condition at 473.623 K. The acetate, which was stable in O2 or NO, was reactive in NO+O2. Nitrates, which were relatively stable in n-hexane, were quite reactive toward n-hexane+O2. The rate of nitrates reaction in n-hexane+O2 was close to the steady-state rate of NO reduction over wide range of temperature, indicating that the nitrate is a possible intermediate in the SCR. A proposed mechanism, suggesting the reaction of nitrates with partially oxidized hydrocarbon species as a crucial step, explains the steady-state kinetic results. At relatively high NO concentration or at low temperature, nitrates should inhibit the reaction by strongly adsorbing on the catalyst surface.

Radical Type Catalytic Sites on Mesoporous Silica Reviewed

Tadashi Hattori, Takashi Ebigase, Yositaka Inaki, Hisao Yoshida, and Atsushi Satsuma

Stud. Surf. Sci. Catal. Vol. 129 page： 837 2000

Acid strength of support materials as a factor controlling catalytic activity of noble metal catalysts for catalytic combustion Reviewed

Yoshiteru Yazawa, Naonobu Takagi, Noriko Kagi, Akiko Ishikawa, Shin-ichi Komai, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 130C page： 2189 2000

Influence of intracrystalline diffusion on the selective catalytic reduction of NO by hydrocarbon over Cu-MFI zeolite Reviewed

Akira Shichi, Atsushi Satsuma, Shin-ichi Komai and Tadashi Hattori

Appl. Catal. B Vol. 24 page： 97 2000

Effects of Methane and Oxygen in Decomposition of Nitrous Oxide over Metal Oxide Catalysts Reviewed

Atsushi Satsuma, Hajime Maeshima, Kiyoshi Watanabe, and Tadashi Hattori

Catal. Today Vol. 63 ( 2-4 ) page： 347 2000

Mechanism of NO Reduction by CH4 in the Presence of O2 over Pd-H-Mordenite Reviewed

Ken-ichi, Shimizu, Humio Okada, Yasuhisa Nakamura, Atsushi Satsuma, and Tadashi Hattori

J. Catal. Vol. 195 ( 1 ) page： 151 2000

Molecular design of highly dispersed transition-metal oxide catalysts for selective catalytic reduction of NO by hydrocarbons Reviewed

Ken-ichi Shimizu, Hajime Maeshima, Hisaya Kawabata, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 130B page： 1403 2000

Low temperature radical oxidation of butane over in-situ prepared silica species Reviewed

Atsushi Satsuma, Naruaki Sugiyama, Yuichi Kamiya, and Tadashi Hattori

Stud. Surf. Sci. Catal. Vol. 130B page： 1799 2000

Spectroscopic characterization of Cu-Al2O3 catalysts for selective reduction of NO with propene Reviewed

Ken-ichi Shimizu, Hajime Maeshima, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Phys. Chem. Chem. Phys. Vol. 2 page： 2435 2000

Formation and reactions of isocyanic acid during the catalytic reduction of nitrogen oxides Reviewed

Noel W. Cant, Dean C. Chambers, Andrew D. Cowan, Irene O. Y. Liu, and Atsushi Satsuma

Topics in Catalysis Vol. 10 page： 13 2000

Intermediates in the Selective Reduction of NO by Propene over Cu-Al2O3 Catalysts: Transient in situ FTIR Study Reviewed

Ken-ichi Shimizu, Hisaya Kawabata, Hajime Maeshima, Atsushi Satsuma, and Tadashi Hattori

J. Phys. Chem. B Vol. 104 ( 13 ) page： 2885 2000

Structure Sensitive Reaction over Calcium Oxide - Decomposition of Nitrous Oxide Reviewed

Atsushi Satsuma, Ryugo Akahori, Masatoshi Kato, Shin-ichi Komai, Hisao Yoshida and Tadashi Hattori

J. Mol. Catal. A Chemical Vol. 155 page： 81 2000

Catalytic performance of Ag-Al2O3 catalyst for the selective reduction of NO by higher hydrocarbons Reviewed

Ken-ichi Shimizu, Atsushi Satsuma, and Tadashi Hattori

Appl. Catal. B Vol. 25 page： 239 2000

Dimethylpyridine-Temperature Programmed Desorption (DMP-TPD) for Measurement of Strength of Bronsted and Lewis Acid Sites on Metal Oxide Catalysts Reviewed

Atsushi Satsuma, Yuichi Kamiya, Yenni Westi and Tadashi Hattori

Appl. Catal. A Vol. 194-195 page： 253 2000

Crystal field effect on the chemical shift in Cu L3 XANES spectra of copper(II) compounds Reviewed

Ken-ichi Shimizu, Hajime Maeshima, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Chem. Lett. Vol. 2000 page： 210 2000

Number of surface redox sites of V-Sb-O catalysts Reviewed

Atsushi Satsuma, Satit Phiyanalinmat, Miki Yashiro, and Tadashi Hattori

J. Chem. Intermd. Vol. 26 ( 2 ) page： 113 2000

Enhanced de-NOx performance of Ag-aluminate catalyst by increasing carbon number of hydrocarbon reductants Reviewed

Ken-ichi Shimizu, Junji Shibata, Atsushi Satsuma and Tadashi Hattori

Chem. Lett. Vol. 1999 page： 1079 1999

Role of Acetate and Nitrates in the Selective Catalytic Reduction of NO by Propene over Alumina Catalyst as Investigated by FTIR

Journal of Physical Chemistry B. Vol. 103 ( 25 ) page： 5240-5245 1999

Al K-edge XANES Study for the Quantification of Aluminum Coordination in Alumina Reviewed

Ken-ichi Shimizu, Yuko Kato, Tomoko Yoshida, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Chem. Commun. page： 1681-1682 1999

Acid Strength of Support Materials as a Factor Controlling Oxidation State of Palladium Catalyst for Propane Oxidation Reviewed

Yoshiteru Yazawa, Hisao Yoshida, Nobuyuki Takagi, Shin-ichi Komai, Atsushi Satsuma and Tadashi Hattori

J. Catal. Vol. 187 page： 15-23 1999

XANES Study of the Support Effect on the State of Platinum Catalysts Reviewed

Hisao Yoshida, Yoshiteru Yazawa, Nobuyuki Takagi, Atsushi Satsuma, Tsunehiro Tanaka, Satohiro Yoshida, and Tadashi Hattori,

J. Synchrotron Rad., 6, 471-473 (1999). Vol. 6 page： 471-473 1999

Deconvolution Analysis of Cu L-Edge XANES for Quantification of Copper (II) Coordinations in Copper-aluminate Catalysts Reviewed

Ken-ichi Shimizu, Hajime Maeshima, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Jpn. J. Appl. Phys., Suppl. Vol. 38 ( 1 ) page： 44-46 1999

Combustion of a Trace Amount of Methane in the Presence of Water Vapor over Pd Catalysts Using ZrO2 as a Support Reviewed

Kazuhiro Nomura, Kiyoshi Noro, Yasuhisa Nakamura, Yoshiteru Yazawa, Hisao Yoshida, Atsushi Satsuma, and Tadashi Hattori

Catal. Lett. Vol. 58 page： 127-130 1999

FTIR Studies of the Origin of Deactivation during the Decomposition of Nitromethane on Co-ZSM5 Reviewed

Atsushi Satsuma, Andrew D. Cowan, Noel W. Cant, and David L. Trimm

J. Catal. Vol. 181 page： 165-169 1999

Alunima-Supported Gallium Oxide Catalysts for NO Selective Reduction: Influence of the Local Structure of Surface Gallium Oxide Species on the Catalytic Activity Reviewed

Ken-ichi Shimizu, Mikio Takamatsu, Koji Nishi, Hisao Yoshida, Atsushi Satsuma, Tsunehiro Tanaka, Satohiro Yoshida, and Tadashi Hattori

J. Phys. Chem. B Vol. 103 page： 1542-1549 1999

FTIR Studies of the Origin of Deactivation during the Decomposition of Nitromethane on Co-ZSM5

Journal of Catalysis Vol. 181 page： 165-169 1999

Selective Catalytic Reduction of NO by hydrocarbons on Ga23/Al2O3 Catalysts

Applied Catalysis B : Environmental Vol. 16 ( 4 ) page： 319-326 1998

Reactivity of Surface Nitrate Species in the Selective Reduction of NO with Propene over Na-H-mordenite as Investigated by Dynamic FT/IR Spectroscopy

Journal of Chemical Society, Faraday Transaction Vol. 94 ( 2 ) page： 301-307 1998

Determination of surface V=O species of V2O5 catalysts under reaction condition using in-situ NARP technique

Research on Chemical Intermediates Vol. 24 ( 4 ) page： 425-437 1998

Transition metal-aluminate catalysts for NO reduction by C3H6

Applied Catalysis, B : Environmental Vol. 18 page： 163-170 1998

Formation and Reaction of Surface Acetate on Al2O3 during NO reduction by C3H6

Applied Catalysis, B : Environmental Vol. 19 page： L87-92 1998

Low Temperature Selective Reduction of NO with Propene over Alkaline-exchanged Mordenites(共著)

Catalysis Letters Vol. 45 ( 4 ) page： 267-269 1997

Activity of Surface Species of(VO2P2O7 on Oxidation of Butane

Applied Surface Science Vol. 121 page： 496-499 1997

Novel Method for Preparation of High Surface Area SnO2 -Solvent Replacement by Alchol(共著)

Chemistry Letters Vol. 1997 ( 3 ) page： 279 1997

Radical Type Catalytic Oxidation of Butane at Low Temperatures over in-situ Prepared Silica Species

Chemistry Letters Vol. 1997 page： 1051-1052 1997

Marked Effect of Preparation Method of V2O5/TiO2 (rutile)Catalysts in the Selective Oxidation of Benzene(共著)

Chemistry Letters Vol. 1996 ( 12 ) page： 1115-1116 1996

Crystal-Plane-Specific Population of Surface V=O Species on (VO)2P2O7 (共著)

Studies in Surface Science and Catalysis Vol. 92 page： 281-286 1995

Dependence of Selective Reduction of NO with C3H6 on Acid Properties of Ion-Exchanged Zeolites(共著)

Catalysis Letters Vol. 31 page： 367-375 1995

Factors Determining the Selective Exposure of (010) Plane of V2O5-Catalysis Supported on Various TiO2 (共著)

Research on Chemical Intermediates Vol. 21 ( 2 ) page： 95-114 1995

Effect of Acid Sites on Deactivation of Methanol Conversion over Modified Mordenites

Kagaku Kogaku Ronbunshu Vol. 21 ( 6 ) page： 1120 1995

Effect of Additives on the Active Sites of (VO)2P2O7 Catalysts(共著)

Catalysis Today Vol. 16 page： 113-121 1993

Crysta-Plane-Specific Effect of Promoters on Active Sites of V2O52 Catalyst(共著)

Journal of Physical Chemistry Vol. 95 page： 8 1991

Number of surface V=O species of Promoted (VO)2P2O7 catalysts(共著)

Applied Catalysis Vol. 69 page： pL1-L5 1991

Number of Surface V=O Species of Promoted (VO)2P2O7 Catalysts(共著)

Applied Catalysis page： 69 1991

Promotion Effects of Various Oxides on Oxidation of Benzene over Vanadium Pentoxide Catalysts(共著)

Applied Catalysis page： 72 1991

Effect of Promoters on Activity and Selectivity of Benzene Oxidation on V2O5 Catalysts : Study by Well-Defined V2O5 Catalysts(共著)

Studies in Surface Science and Catalysis page： 55 1990

Enhanced Activity of Promoted (VO)2P27 by Preferential Exposure of the (020) Plane(共著)

Journal of Chemical Society, Chemical Communications page： 1337 1990

Enhanced Activity of Promoted (VO)2P2O7 by Preferntial Exposure of the (020) Plane(共著)

Journal of Chemical Society, Chemical Communications 1990

Sufrace Active Sites of V2O5-SnO2 Catalysts(共著)

Journal of Phy-ical Chemistry Vol. 94 page： 15 1990

Sufrace Active Sites of V2O3-MoO3 Catalysts(共著)

Journal of Physical Chemistry Vol. 93 page： 4 1989

HCl-Vapour-Etching for the Prepartation of Monolayer V2O5/TiO2 Catalysts with High Expoure of Active Sites(共著)

Chemistry Letters 1989

Surface Active Sites of V2O5-WO3 Catalysts(共著)

Journal of Physical Chemistry Vol. 92 page： 21 1988

Surface Chemical Structure of V2O5-P2O5 Catalysts(共著)

Journal of Physical Chemistry Vol. 92 page： 8 1988

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