<em>In Situ</em> X-ray Absorption Spectroscopy of a Synergistic Co?Mn Oxide Catalyst for the Oxygen Reduction Reaction [electronic resource]
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| Format: | Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy. Office of Basic Energy. Energy Frontier Research Centers (EFRC) ; Distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2019.
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| Abstract: | Identifying the catalytically active site(s) in the oxygen reduction reaction (ORR), under real-time electrochemical conditions, is critical to the development of fuel cells and other technologies. We have employed in situ synchrotron-based X-ray absorption spectroscopy (XAS) to explore the synergistic interaction of a Co?Mn oxide catalyst which exhibits impressive ORR activity in alkaline fuel cells. X-ray absorption near edge structure (XANES) was used to track the dynamic structural changes of Co and Mn under both steady state (constant applied potential) and nonsteady state (potentiodynamic cyclic voltammetry, CV). Under steady state conditions, both Mn and Co valences decreased at lower potentials, suggesting the conversion from Mn-(III,IV) and Co(III) to Mn(II,III) and Co(II), respec-tively. Rapid X-ray data acquisition, combined with a slow sweep rate in CV, enabled a 3 mV resolution in the applied potential, approaching a nonsteady (potentiody-namic) state. Changes in the Co and Mn valence states were simultaneous and exhibited periodic patterns that tracked the cyclic potential sweeps. To the best of our knowledge, this represents the first study, using in situ XAS, to resolve the synergistic catalytic mechanism of a bimetallic oxide. Strategies developed/described herein can offer an enticing approach to unveil the reaction mechanism for other multimetallic electrocatalysts. |
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| Item Description: | Published through Scitech Connect. 01/15/2019. "Journal ID: ISSN 0002-7863" Yang, Yao ; Wang, Ying ; Xiong, Yin ; Huang, Xin ; Shen, Luxi ; Huang, Rong ; Wang, Hongsen ; Pastore, James P. ; Yu, Seung-Ho ; Xiao, Li ; Brock, Joel D. ; Zhuang, Lin ; AbruᬠH飴or D. ; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22) National Science Foundation (NSF) National Natural Science Foundation of China (NNSFC) |
| Physical Description: | Size: p. 1463-1466 : digital, PDF file. |