| Project/Area Number |
17550073
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Analytical chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
IZUMI Yasuo Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Associate Professor, 大学院総合理工学研究科, 講師 (50251666)
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| Co-Investigator(Kenkyū-buntansha) |
BABA Toshihide Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Professor, 大学院総合理工学研究科, 教授 (50165057)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Catalytic, chemical processes / Radiation, X-ray, Corpuscular beam / Nano-materials / Structural, functional materials / Analyses, Evaluation / Nano-particles / Gold / Tin / 酸化触媒 / 選択水素化 |
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| Research Abstract |
This work was performed as the extension of series of our state-sensitive XAFS(X-ray absorption fine structure) studies applied to catalysts and environmental materials. State-sensitive Sn Kα_1-selecting XAFS spectra were measured for Pt-Sn catalysts suppressing the core-hole lifetime broadening of Sn K level. The presence of Sn sites adsorbed on Pt particles (mean particle size approximately equal 1 nm) highly dispersed over SiO_2 surface and the electronic state of Sn were demonstrated. Also, series of Au/TiO_2 catalysts were synthesized. The mean Au particle size was controlled homogeneous to between 2.9 and 8.7 nm. Based on state-sensitive Au Lα_1-selecting XAFS, the presence of neutra1, δ^-, and δ^+ sites were demonstrated in Au nano-particles.
First major, remarkable progress during this period was that the improvement of energy resolution of state-sensitive XAFS due to the advancement of X-ray beam stability at SPring-8 beamline. The beam position stability exhibited similar effect to reduce the beam size at the sample position. As the result, the state-sensitive structural analyses of each site in Au nano-particles became more familiar, technically less-demanding. Second, in common with our study of vanadium catalysts excited under visible light (Priority Area Research "Nano-Dynamics"), measurement technique of state-sensitive XAFS under on-reaction conditions was established. As the result, we were successful to directly detect electron donation from Au(δ^+)sites to O_2 molecule under on-reaction condition. The measurement is regarded as to detect the key intermediate in the low-temperature CO oxidation.
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