Role of Cerium Oxide in the Enhancement of Activity for the Oxygen Reduction Reaction at Pt鈥揅eOx Nanocomposite Electrocatalyst - An in Situ Electrochemical X-ray Absorption Fine Stru

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• 作者：Takuya Masuda ; Hitoshi Fukumitsu ; Keisuke Fugane ; Hirotaka Togasaki ; Daiju Matsumura ; Kazuhisa Tamura ; Yasuo Nishihata ; Hideki Yoshikawa ; Keisuke Kobayashi ; Toshiyuki Mori ; Kohei Uosaki
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：May 10, 2012
• 年：2012
• 卷：116
• 期：18
• 页码：10098-10102
• 全文大小：278K
• 年卷期：v.116,no.18(May 10, 2012)
• ISSN：1932-7455

文摘

In situ electrochemical X-ray absorption fine structure (XAFS) measurements were performed at the Pt L₃ and Ce L₃ edges of the Pt鈥揅eO_x/C catalyst, which was prepared by a combined process of precipitation and coimpregnation methods, as well as at the Pt L₃ edge of the conventional Pt/C catalyst in oxygen-saturated H₂SO₄ solution to clarify the role of CeO_x in the reduction of the overpotential for the oxygen reduction reaction (ORR) at the Pt鈥揅eO_x nanocomposite compared with the conventional Pt/C catalyst. XAFS measurements clearly show that the enhancement of ORR activity is attributed to the inhibition of Pt oxide formation by the CeO_x layer, of which Ce³⁺ was oxidized to Ce⁴⁺ instead of Pt at the Pt oxide formation potential.