2006 Fiscal Year Final Research Report Summary
In situ Analysis of Hydrotreatment Catalysts with combined XAFS and IR
| Project/Area Number |
16360405
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Catalyst/Resource chemical process
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
BANDO Kyoko K. National Institute of Advanced Industrial Science and Technolog, Research Institute of Sustainable Chemistry, Senior Researcher, 環境化学技術研究部門, 主任研究員 (50357828)
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| Co-Investigator(Kenkyū-buntansha) |
IMAMURA Motoyasu National Institute of Advanced Industrial Science and Technolog, National Metrology Institute of Japan, Senior Researcher, 計測標準研究部門, 主任研究員 (20356520)
KUBOTA Takeshi Shimane University, Faculty of Science and Engineering, 総合理工学部, 助手 (90304253)
ICHIKUNI Nobuyuki Chiba University, 工学部, 助教授 (40261937)
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| Project Period (FY) |
2004 – 2006
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| Keywords | in situ / XAFS / IR / Pd-Pt / HDA / HDS / Structure / 活性サイト構造 |
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| Research Abstract |
The aim of this project was to develop a new XAFS analysis technique which enables simultaneous analysis of in-situ XAFS and in-situ IR for the catalyst under reaction conditions. And it is applied to analysis of Pd-Pt catalysts which are active for hydrotreatment reactions.
For the development of the new technique, it was needed to irradiate X-ray and IR to the same sample simultaneously and measure absorbance separately. Since the XAFS measurement was carried out at XAFS beam lines in Photon Factory (PF-IMSS-KEK) and the XAFS measurement system was already equipped, the IR measurement system should have been adjusted to the XAFS system. Therefore, the IR beam was extracted from a source and lead to the reaction cell with an optical fiber. The in-situ gas phase reaction cell was designed in a cross-shape to introduce X-ray and IR, and the sample was placed at the center of the cell, where the two beams intersected each other at right angles and at 45° to the sample.
The in-situ XAFS and IR analysis was applied to Pd-Pt catalysts to elucidate the precise structure of active metal particles, especially the composition of the outer surface exposed to reactants. We carried out measurements during CO adsorption and a subsequent temperature programmed reduction process. The change in Pd K-edge and Pt L_<III>-edge XAFS was compared with that observed in IR. The change in the total intensity of IR bands assigned to ν(VO) well corresponded to the amount of metal species with adsorbed CO, which was estimated by pattern fitting analysis of XANES. The metal species whose electronic state was changed by CO adsorption could be the ones located on the outer surface and these species are discernible by XAFS. The result was presented in the 13^<th> international conference on XAFS
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