2003 Fiscal Year Final Research Report Summary
Study of Interface and Catalytic Activity on Core-Shell Structured Noble Metal Alloy Nanoparticles
| Project/Area Number |
14550658
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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 |
Physical properties of metals
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| Research Institution | KYOTO UNIVERSITY (2003)
Osaka Prefecture University (2002) |
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Principal Investigator |
KOBAYASHI Yasuhiro Kyoto Univ., Research Reactor Institute, Assistant, 原子炉実験所, 助手 (00303917)
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| Co-Investigator(Kenkyū-buntansha) |
SETO Makoto Kyoto Univ., Research Reactor Institute, Assistant Professor, 原子炉実験所, 助教授 (40243109)
TANIGUCHI Ryoichi Osaka Prefecture Univ., Research Institute for Advanced Science and Technology, Lecturer, 先端科学研究所, 講師 (60155215)
HORI Fumitoshi Osaka Prefecture Univ., Research Institute for Advanced Science and Technology, Assistant, 先端科学研究所, 助手 (20275291)
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| Project Period (FY) |
2002 – 2003
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| Keywords | AuPd nanoparticle / core-shell structure / ultrasonic reduction technique / Mossbauer spectroscopy / EXAFS / positron annihilation / high-resolution transmission electron microscope / catalytic activity / 触媒活性 |
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| Research Abstract |
We prepared the Au-core and Pd-shell structured nanoparticles by the ultrasonic reduction technique. The diameters of the particles are about 4〜12 nm. On the core-shell structured AuPd nanoparticles, there is the high catalytic activity on hydrogenate of 4-penteonic acid. To elucidate the electronic structure of these nanoparticles, we measured ^<197>Au Mossbauer spectroscopy, EXAFS, positron annihilation and high-resolution transmission electron microscope (TEM). On ^<197>Au Mossbauer study, the spectra contain two components, one, is component due to the pure Au, and the other is due to the AuPd alloy. From the area ratio of these components, it is shown that there is the AuPd alloy layer between Au-core and Pd-shell and the thickness of the alloy layer is about 3 atom layers. The result of EXAFS on Pd K edge shows existence of the AuPd alloy layer. The expansion of the atomic distance on the Pd shell is observed by the XAFS measurements. By the positron annihilation coincidence Doppler broadening measurement (CDB), the electronic state of the surface of the nanoparticles are observed. To observe the cross section of the nanoparticles by TEM, we used the ultra microtome and developed the conditions for TEM observation.
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