Faculty Profiles - SATSUMA, Atsushi

Papers - SATSUMA, Atsushi

Division display 21 - 40 of about 274 ／ All the affair displays >>

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

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

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

Scopus

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

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Web of Science

Scopus

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

Scopus

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

　 PREV - NEXT 　

<SATSUMA, Atsushi>

Papers - SATSUMA, Atsushi