Structural defects working as active oxygen-reduction sites in partially oxidized Ta-carbonitride core-shell particles probed by using surface-sensitive conversion-electron-yield x-ray absorption spectroscopy
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- Hideto Imai
- NEC Corporation 1 Nano Electronics Research Laboratories, , 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan
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- Masashi Matsumoto
- NEC Corporation 1 Nano Electronics Research Laboratories, , 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan
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- Takashi Miyazaki
- NEC Corporation 1 Nano Electronics Research Laboratories, , 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan
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- Shinji Fujieda
- NEC Corporation 1 Nano Electronics Research Laboratories, , 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan
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- Akimitsu Ishihara
- Yokohama National University 2 Chemical Energy Laboratory, , 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
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- Motoko Tamura
- Yokohama National University 2 Chemical Energy Laboratory, , 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
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- Ken-ichiro Ota
- Yokohama National University 2 Chemical Energy Laboratory, , 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
説明
<jats:p>We analyzed the local structure of the surface Ta-oxide phase of TaCN/Ta2O5 core-shell particles that have a high oxygen reduction activity by using surface-sensitive conversion-electron-yield x-ray absorption spectroscopy, suppressing the contribution from the TaCN cores. The radial structure analysis revealed that the catalytically-active Ta2O5 phase in the TaCN/Ta2O5 particle surface contains oxygen-vacancy defects with shorter Ta–O bonds leading to the slight expansion of the first Ta–O shell. Such oxygen defects are likely responsible for the oxygen reduction capability by creating electronically favorable oxygen adsorption sites and electron conduction pathways.</jats:p>
収録刊行物
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- Applied Physics Letters
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Applied Physics Letters 96 (19), 2010-05-10
AIP Publishing
