研究者詳細 - 沢邊　恭一

論文 - 沢邊　恭一

分割表示 >> ／全件表示 66 件中 1 - 66 件目

Reversible Multi-Complexation of CO<sub>2</sub> to Alkaline Earth Metal Ion-Pair at 400 ppm and 298 K 査読有り

Oda, A; Sawabe, K; Satsuma, A

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 63 巻 ( 51 ) 2024年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

Murata, K; Oda, A; Satsuma, A; Sawabe, K

JOURNAL OF PHYSICAL CHEMISTRY C 127 巻 ( 41 ) 頁： 20267 - 20275 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

Theoretical Study on Carbon Monoxide Adsorption on Unsupported and γ‐Al₂O₃‐Supported Silver Nanoparticles: Size, Shape, and Support Effects 査読有り

Sawabe, Kyoichi and Satsuma, Atsushi

ACS Omega 7 巻頁： 4405 - 4412 2022年1月

Encapsulated Platinum-Tin Nanoparticles in Silicalite-1 Zeolite for Methylcyclohexane Dehydrogenation 査読有り

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

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 13 巻 ( 9 ) 頁： 3608 - 3621 2025年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

ACS CATALYSIS 15 巻 ( 4 ) 頁： 3191 - 3202 2025年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

JOURNAL OF MATERIALS CHEMISTRY A 12 巻 ( 34 ) 頁： 22655 - 22667 2024年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

Rutile TiO<sub>2</sub>-Supported Pt Nanoparticle Catalysts for the Low-Temperature Oxidation of Ethane to Ethanol 査読有り

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

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 29 ) 頁： 20122 - 20132 2024年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

トルエン水素化を革新的に促進する省貴金属なヘテロアトムアンサンブルサイトの設計招待有り

織田晃,沢邊恭一,薩摩篤

触媒 66 巻 ( 5 ) 頁： 266 - 271 2024年

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

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

JOURNAL OF MATERIALS CHEMISTRY A 11 巻 ( 44 ) 頁： 23854 - 23866 2023年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

ACS CATALYSIS 13 巻 ( 15 ) 頁： 10026 - 10040 2023年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

CATALYSIS TODAY 411 巻頁： 113814 - 113819 2023年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

CATALYSIS SCIENCE & TECHNOLOGY 12 巻 ( 18 ) 頁： 5488 - 5494 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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 126 巻 ( 19 ) 頁： 8312 - 8326 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

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

CATALYSIS SCIENCE & TECHNOLOGY 12 巻 ( 9 ) 頁： 2749 - 2754 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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

Sawabe, K; Satsuma, A

ACS OMEGA 7 巻 ( 5 ) 頁： 4405 - 4412 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Omega

Nanoparticles (NPs) supported on metal oxides exhibit high catalytic activities for various reactions. The shape and oxidation state of such NPs, which are related to the catalytic activity, are often determined by the support. Herein, we conducted a density functional theory study on isolated silver (Ag) NPs and two types of Ag-NPs supported on gamma-aluminum oxide (γ-Al2O3). First, carbon monoxide (CO) adsorption on the isolated Ag NPs was investigated for decahedra (D5h), icosahedra (Ih), and cuboctahedra (Oh) of various sizes. Ih and Oh NPs showed moderate size dependence, whereas D5h NPs showed high size dependence when the height was below 1.4 nm. The enhancement of CO adsorption on D5h NPs was attributed to the presence of superatomic states. Next, we performed geometrical optimization of Ag54/γ-Al2O3(110) with a decahedral shape. Two types of structures were obtained: amorphous Ag54(A) and locally fivefold symmetrical Ag54(B) structures. Both NPs on γ-Al2O3(110) were found to be positively charged, but electron transfer to the support occurred only from the Ag atoms at the two bottom layers, and the upper part of NPs was relatively neutral. The enhancement of CO adsorption on Ag54(B) disappeared due to loss of the high symmetry. In turn, the moderate size dependence of neutral isolated NPs can be applied.

DOI： 10.1021/acsomega.1c06208

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

Oda, A; Aono, K; Murata, N; Murata, K; Yasumoto, M; Tsunoji, N; Sawabe, K; Satsuma, A

CATALYSIS SCIENCE & TECHNOLOGY 12 巻 ( 2 ) 頁： 542 - 550 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Catalysis Science and Technology

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 ∼50 mmol gcat−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 ∼200 mmol gcat−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

Identification of a Stable Ozonide Ion Bound to a Single Cadmium Site within the Zeolite Cavity

Oda, A; Sawabe, K; Ohkubo, T; Kuroda, Y

JOURNAL OF PHYSICAL CHEMISTRY C 126 巻 ( 1 ) 頁： 261 - 272 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physical Chemistry C

Molecular metal oxides are invoked as the key intermediate in a variety of oxidative reactions. Although an atomic oxygen ligand and molecular O2 ligands are well known, the triatomic oxygen ligand (ozonide) is very limited due to its instability. Here, we report a successful preparation and characterization of stable cadmium ozonide species. Our approach used the negatively charged local environments within the zeolite pore, which allowed us to isolate the single cadmium ozonide species as the counter cation even at room temperature. Its state was characterized by vibronic progressions closely similar to those observed in the cryogenic inert-element matrix system. Density functional theory calculations determined the lowest-energy geometry as the side-on [CdII(O3–•)]+ having C2v symmetry. This model was stable within the ab initio molecular dynamics simulation at 300 K, rationalizing the abnormal stability of [CdII(O3–•)]+observed experimentally. The O3-a1 → Cd-5s-donation orbital interaction was the driving force for the formation of the stable CdII–(O3–•) bond. The zeolite lattice plays a pivotal role in the enhancement of the acidity of the cadmium ion and stabilizes the donation interaction but constrains the O3 adduct as a pseudo-free ozonide ion. The findings in the present work will be applicable for designing new metal ozonide compounds.

DOI： 10.1021/acs.jpcc.1c09277

<SUP>17</SUP>O-ESR Evidence for Zeolite Matrix Isolation of a Square Planar ZnO<sub>3</sub> Ring Radical with <i>C</i><sub>2v</sub> Symmetry

Oda, A; Kumagai, J; Sawabe, K; Ohkubo, T; Kuroda, Y; Satsuma, A

JOURNAL OF PHYSICAL CHEMISTRY C 125 巻 ( 9 ) 頁： 5136 - 5145 2021年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physical Chemistry C

Atomic-level insights into the geometric and electronic states of the metal-ozonide sequence remain scarce. We have recently found that a zeolite catalyst has a local environment to isolate the extremely rare mononuclear ZnII- ozonide species. In the present study, each atomic oxygen radical of the ZnII-ozonide species was selectively labeled with 17O, and each local environment was analyzed by electron spin resonance (ESR) spectroscopy at an X-band frequency, computer simulations of ESR spectra, density functional theory (DFT) calculations, and ab initio molecular dynamics (AIMD) simulations. The two types of 17O hyperfine structures assignable to the C2v geometry of a square planar ZnO3 ring radical were obtained experimentally. The DFT calculations ascertained the ground-state C2v geometry of the ZnII-ozonide adduct. This model provides 17O-hyperfine coupling constants that correspond well with the experimental parameters, supporting the generation of the C2v ZnO3 ring radical. The C2v ZnO3 ring radical is stable even at around room temperature, as evidenced by the similarity in the ESR spectra collected at 300 and 4 K. Such an unusual stability was supported by AIMD simulations, where C2v geometry was preserved at least for 50 ps at 300 K. Molecular orbital analyses showed that the ozonide species is stabilized via the highly polarized ZnII-(O3 - ) bonds. These interactions led to the polarization of two O-O bonds in the ozonide adduct, through which both side oxygens becomes anionic states, but the central oxygen becomes a cationic state. The zeolite lattice plays a pivotal role in constraining the effective charge of Zn close to (+2) and thereby stabilizing such a highly polarized ZnII-(O3 - ) bond. These novel findings suggest that the zeolite lattice has the potential as the ligand to create reactive metal-oxygen radicals with an unprecedented shape and ionic states.

DOI： 10.1021/acs.jpcc.1c01042

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 11 巻 ( 21 ) 頁： 9426 - 9431 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

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 10 巻 ( 20 ) 頁： 12333 - 12339 2020年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Catalysis

The key reactive sites in the selective catalytic reduction (SCR) of NO using ammonia (NH3-SCR) are the Cu(II)/Cu(I) ammine complexes encapsulated within zeolite catalysts. The reaction intermediate in the important CuI → CuII reoxidation step has been proposed as the dicopper species. However, obtaining the definitive spectroscopic probe for the dicopper intermediate under NH3-SCR remains a quite challenging subject. Here we report spectroscopic evidence of the efficient generation of the dicopper intermediate in NH3-SCR over Cu-ion-exchanged zeolites. The state of the Cu ion under the NH3-SCR condition was analyzed using fiber-optic UV-vis-NIR spectroscopy; a distinct spectroscopic fingerprint of the (μ-η2:η2-peroxo)dicopper(II) intermediate was detected. Our spectroscopic assignment was rationalized by density functional theory calculations. The intensity of the spectroscopic fingerprints of dimeric copper was much higher than expected from previous reports, and it was also found that such a spectroscopic probe is observable only under the NH3-SCR conditions. This finding strongly supports the previously suggested Cu dynamic contributions to NH3-SCR catalysis.

DOI： 10.1021/acscatal.0c03425

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

Tsuchiya, A; Masaoka, S; Ohyama, J; Sawabe, K; Satsuma, A

CATALYSIS SCIENCE & TECHNOLOGY 10 巻 ( 12 ) 頁： 3868 - 3874 2020年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Catalysis Science and Technology

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

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

Murata, K; Ogura, K; Ohyama, J; Sawabe, K; Yamamoto, Y; Arai, S; Satsuma, A

ACS APPLIED MATERIALS & INTERFACES 12 巻 ( 23 ) 頁： 26002 - 26012 2020年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Materials and Interfaces

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

Structure-Activity Relationship of Iron Oxides for NO Reduction in the Presence of C<sub>3</sub>H<sub>6</sub>, CO, and O<sub>2</sub>

Ueda, K; Ohyama, J; Sawabe, K; Satsuma, A

CHEMISTRY-A EUROPEAN JOURNAL 25 巻 ( 61 ) 頁： 13964 - 13971 2019年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry - A European Journal

Spinel-type NiFe2O4 exhibited the highest NO reduction activity among base-metal oxides under simulated exhaust of a gasoline-powered vehicle. The structure–activity relationship of iron oxides has been investigated through both experimental and computational studies. Spinel iron oxide (γ-Fe2O3) exhibited a much higher NO reduction activity than that of iron oxide with other structures (α-Fe2O3 and LaFeO3). Operando IR measurements clarified that the spinel structure facilitated the reaction between NOx and adsorbed oxidized hydrocarbon or cyanide species. The high reactivity of the spinel structure was ascribed to the high adsorption energy of NO, as elucidated by DFT calculations. Furthermore, molecular orbital calculations demonstrated that the local coordination structure of the spinel iron oxide induced the involvement of not only σ but also π orbitals during NO adsorption on Fe atoms. This work clarified the origin of the structure-dependent activity of metal oxides, with a focus on their local coordination structures.

DOI： 10.1002/chem.201902994

金属酸化物とバイメタルで開拓する非貴金属自動車触媒招待有り

植田格弥,馬原優治,大山順也,沢邊恭一,薩摩篤

ファインケミカル 48 巻 ( 4 ) 頁： 31-37 2019年4月

Synthesis of Supported Bimetal Catalysts using Galvanic Deposition Method

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

CHEMICAL RECORD 18 巻 ( 9 ) 頁： 1306 - 1313 2018年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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

A Theoretical Insight into Enhanced Catalytic Activity of Au by Multiple Twin Nanoparticles 招待有り査読有り

Kyoichi Sawabe, Taiki Koketsu, Junya Ohyama and Atsushi Satsuma

Catalysts 7 巻頁： 191 2017年6月

A Theoretical Insight into Enhanced Catalytic Activity of Au by Multiple Twin Nanoparticles 査読有り Open Access

Sawabe, K; Koketsu, T; Ohyama, J; Satsuma, A

CATALYSTS 7 巻 ( 6 ) 2017年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Catalysts

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

Ag-M (M: Ni, Co, Cu, Fe) bimetal catalysts prepared by galvanic deposition method for CO oxidation 査読有り

Yuji Mahara, Hiroyuki Ishikawa1, Junya Ohyama, Kyoichi Sawabe, Atsushi Satsuma

Catalysis Today 265 巻頁： 2-6 2016年

Substrate-Specific Heterogeneous Catalysis of CeO2 by Entropic Effects via Multiple Interactions 査読有り

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

ACS Catal. 5 巻頁： 20-26 2015年

Enhanced CO Oxidation Activity of Ni@Ag Core Shell Nanoparticles 査読有り

Yuji Mahara,Hiroyuki Ishikawa, Junya Ohyama,Kyoichi Sawabe,Yuta Yamamoto,Shigeo Arai,,Atsushi Satsuma

Chem. Lett. 43 巻頁： 910-912 2014年

Density-Functional Theoretical Study on the Role of Lewis and Brønsted Acid Sites on CeO2(110) Surfaces for Nitrile Hydration 査読有り

Kyoichi Sawabe , Yukio Yoshikawa, Atsushi Satsuma

Top. Catal. 57 巻頁： 1094-1102 2014年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Hydration of cyanopyridine on CeO2(110) surfaces was studied using periodic DFT+U calculations.One of two adsorption modes of 2-cyanopyridine occurs with two-point interaction which causes substrate specificity. A catalytic cycle for the hydration of 2-cyanopyridine was proposed. Cooperativity of Lewis and Brønsted acid sites was found to stabilize the intermediates for the hydration.

DOI： 10.1007/s11244-014-0274-8

自動車排ガス浄化用Aｇクラスター触媒の開発と作用機構研究査読有り

清水研一，沢邊恭一，薩摩篤

触媒 54 巻頁： 228-234 2012年

自動車排ガス浄化用時の再生型Agナノクラスター触媒査読有り

清水研一，沢邊恭一，薩摩篤

化学工業 63 巻頁： 213-218 2012年

Hydration of nitriles to amides in water by SiO2-supported Ag catalysts promoted by adsorbed oxygen atom 査読有り

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

Appl. Catal. 421/422 巻頁： 114-120 2012年

Unique catalytic features of Ag nanoclusters for selective NOx reduction and green chemical reactions 招待有り査読有り

Ken-ichi Shimizu, Kyoichi Sawabe, Atsushi Satsuma

Catal. Sci. Technol. 1 巻頁： 331-341 2011年

Self-Regenerative Silver Nanocluster Catalyst for CO Oxidation 査読有り

Ken-ichi Shimizu, Kyoichi Sawabe, and Atsushi Satsuma

ChemCatChem 3 巻頁： 1290-1293 2011年

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

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

153 巻頁： 90-94 2010年

Oxidant-Free Dehydrogenation of Alcohols Heterogeneously Catalyzed by Cooperation of Silver Clusters and Acid–Base Sites on Alumina 査読有り

Ken-ichi Shimizu, Kenji Sugino, Kyoichi Sawabe, and Atsushi Satsuma

Chem. Eur. J. 15 巻頁： 2341-2351 2009年

Mechanism of Helix Induction in Poly(4-carboxyphenyl isocyanide) with Chiral Amines and Memory of the Macromolecular Helicity and Its Helical Structures 査読有り

Yoko Hase, Kanji Nagai, Hiroki Iida, Katsuhiro Maeda, Noriaki Ochi, Kyoichi Sawabe, Koichi Sakajiri, Kento Okoshi, and Eiji Yashima

J. Am. Chem. Soc. 131 巻頁： 10719-10732 2009年

*Adsorption structure of thiophene on Si(100)-2x1 studied by scanning tunneling microscopy and densitity functional theory 査読有り

Naoki Isobe, Tsutomu Shibayama, Yuichiro Mori, Kosuke Shobatake, Kyoichi Sawabe

Chem. Phys. Lett. 443 巻頁： 347-351 2007年

Energy transfer in hyperthermal Xe-graphite surface scattering 査読有り

Y. Watanabe, H. Yamaguchi, M. Hashinokuchi1, K. Sawabe, S. Maruyama, Y. Matsumoto, and K. Shobatake

Eur. Phys. J. D 38 巻頁： 103-109 2006年

Removal of PCDDs/DFs and dl-PCBs in MWI fly ash by heating under vacuum 査読有り

Y. Misaka, K. Yamanaka, K. Takeuchi, K. Sawabe and K. Shobatake

Chemosphere 64 巻頁： 619-627 2006年

Dechlorination/hydrogenation and destruction reactions of PCDDs in OCDD-added fly ash 査読有り

Y. Misaka, T. Abe, K. Takeuchi, K. Ohba, K. Sawabe and K. Shobatake

Chemosphere 65 巻頁： 419-426 2006年

*ロジウム錯体触媒を用いたアルキンのシリルホルミル化反応機構の理論的研究

48 巻頁： 147-149 2006年

Thermal reaction of polycrystalline AlN with XeF<SUB>2</SUB> 査読有り

M. Watanabe, Y. Mori, T. Ishikawa, H. Sakai, T. Iida, K. Akiyama, S. Narita, K. Sawabe, and K. Shobatake

J. Vac. Sci. Technol. A 23 巻頁： 1647-1656 2005年

*Trampoline motions in Xe-graphite(0001) surface scattering 査読有り

Y. Watanabe, H. Yamaguchi, M. Hashinokuchi, K. Sawabe, S. Maruyama, Y. Matsumoto and K. Shobatake

Chem. Phys. Lett. 413 巻頁： 331-334 2005年

Thermal reaction of polycrystalline SiC with XeF<SUB>2</SUB> 査読有り

M. Watanabe, Y. Mori, H. Sakai, T. Iida, S. Koide, E. Maeta, K. Sawabe, and K. Shobatake

J. Vac. Sci. Technol. A 23 巻頁： 1638-1646 2005年

Surface Characterization of 3C-SiC Exposed to XeF<SUB>2</SUB> 査読有り

M. Watanabe, Y. Mori, H. Sakai, T. Iida, S. Koide, E. Maeta, K. Sawabe, and K. Shobatake

Japanese Journal of Applied Physics 43 巻 ( 406 ) 頁： L346-L348 2004年

X-ray photoelectron spectroscopy of polycrystalline AlN surface exposed to the reactive environment of XeF<SUB>2</SUB> 査読有り

M. Watanabe, Y. Mori, T. Ishikawa, T. Iida, K. Akiyama, K. Sawabe, and K. Shobatake

Applied Surface Science 217 巻 ( 1-4 ) 頁： 82-87 2003年

Thermal Desorption Behavior of AlF<SUB>3</SUB> Formed on Al<SUB>2</SUB>O<SUB>3</SUB> 査読有り

M. Watanabe, T. Iida, K. Akiyama, T. Ishikawa, H. Sakai, K. Sawabe, and K. Shobatake

Japanese Journal of Applied Physics 42 巻 ( 391 ) 頁： L680-L682 2003年

Identification of Desorption Products from the Thermal Reaction of AlN with XeF<SUB>2</SUB> Vapor Using Molecular Beam Mass Spectrometry and a Time-of-Flight Technique 査読有り

M. Watanabe, T. Iida, K. Akiyama, S. Narita, T. Ishikawa, H. Sakai, K. Sawabe, and K. Shobatake

Japanese Journal of Applied Physics 42 巻頁： L356-L358 2003年

Removal of Dioxins in Fly Ash by Vacuum Heat Treatment II. Temperature Dependence and The Outcome Of OCDD 査読有り

T. Abe, K. Takeuchi, Y. Misaka, H. Hattori, M. Itoh, K. Ohba, M. ; Watanabe, T. Imura, K. Sawabe, and K. Shobatake

Organohalogen Compounds 58 巻頁： 149-152 2002年

Removal of Dioxins from Fly Ash by Vacuum Heat Treatment I. Temperature Dependence 査読有り

K. Shobatake, K. Yamanaka, K. Takeuchi, T. Seki, T. Imura, T. Abe, and K. Sawabe

Organohalogen Compounds 54 巻頁： 230-233 2001年

Laser-Induced Photochemistry of Methane on Pt(111): ExcitationMechanism and Dissociation Dynamics 査読有り

Y. Matsumoto, Y. A. Gruzdkov, K. Watanabe and K. Sawabe

Journal of Chemical Physics 105 巻頁： 4775-4788 1996年

The Reactivity of Molecular and Atomic Oxygen in Oxygen-Exchange Reaction between NO and O<SUB>2</SUB> Coadsorbed on a Pt(111) Surface 査読有り

K. Sawabe, Y. Matsumoto, J. Yoshinobu and M. Kawai

Journal of Chemical Physics 103 巻頁： 4757-4764 1995年

Angular Distributions of N<SUB>2</SUB> in Photodissociation of N<SUB>2</SUB>O Adsorbed on a Partially Oxidized Si(100) Surface at 95K 査読有り

J. Lee, H. Kato, K. Sawabe, and Y. Matsumoto

Chemical Physics Letters 240 巻頁： 417-422 1995年

Dynamics of Photochemical Processes of N<SUB>2</SUB>O Adsorbed on Metal and Semiconductor Surfaces

Y. Matsumoto, J. Lee, H. Kato, K. Sawabe

SPIE Proceedings 2125 巻頁： 303-311 1994年

Oxygen-Exchange Reaction between O<SUB>2</SUB> and NO Coadsorbed on a Pt(111) Surface: Reactivity of Molecularly Adsorbed Oxygen 査読有り

K. Sawabe and Y. Matsumoto

Surface Science 303 巻頁： L385-L391 1994年

An Ab Initio Molecular Orbital Study on Adsorption at the MgO surface. II. Site Dependency of Hydrogen Chemisorption on the (MgO)<SUB>4,6,8</SUB> clusters 査読有り

K. Sawabe, N. Koga, K. Morokuma, and Y. Iwasawa

Journal of Chemical Physics 101 巻頁： 4819-4825 1994年

An Ab Initio Molecular Orbital Study on Adsorption at the MgO surface. III. Cooperativity of Ionic Adsorbates 招待有り査読有り

K. Sawabe, K. Morokuma, and Y. Iwasawa

Journal of Chemical Physics 101 巻頁： 7095-7100 1994年

Photochemical C-H Bond Activation of Methane on a Pt(111) Surface 査読有り

Y. A. Gruzdkov, K. Watanabe, K. Sawabe and Y. Matsumoto

Chemical Physics Letters 227 巻頁： 243-247 1994年

Photochemistry and Photodissociation Dynamics of N<SUB>2</SUB>O on Metal Surfaces

Y. Matsumoto, K. Sawabe, and J. Lee

SPIE Proceedings 1858 巻頁： 378-389 1993年

Laser-Induced Photochemistry of Nitrous Oxide on a Pt(111) Surface 査読有り

K. Sawabe and Y. Matsumoto

Surface Science 283 巻頁： 12-131 1993年

Dynamics of the Oxygen Combination Reaction on Pt(111) Initiated by Photodissociation of N<SUB>2</SUB>O at 193 nm: O<SUP>*</SUP>+O(ad) → O<SUB>2</SUB>(g) 査読有り

K. Sawabe, J. Lee, and Y. Matsumoto

Journal of Chemical Physics 99 巻頁： 3143-3146 1993年

Structure of Adsorbed N<SUB>2</SUB>O on a Pt(111) Surface and Photodissociation at 193 nm: Effective Formation of Oxygen Adatoms 査読有り

K. Sawabe and Y. Matsumoto

Chemical Physics Letters 194 巻頁： 45-50 1992年

Influence of Pre- and Postdeposited Au on Coadsorbed CO on Ru(001) 査読有り

K. Sawabe, C. Egawa, T. Aruga, and Y. Iwasawa

Langmuir 5 巻頁： 348-352 1989年

　前のページ - 次のページ　

1