Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction Reaction
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- 作者：Rameshwori Loukrakpam ; Shiyao Shan ; Valeri Petkov ; Lefu Yang ; Jin Luo ; Chuan-Jian Zhong
- 刊名：Journal of Physical Chemistry C
- 出版年：2013
- 出版时间：October 10, 2013
- 年：2013
- 卷：117
- 期：40
- 页码：20715-20721
- 全文大小：449K
- 年卷期：v.117,no.40(October 10, 2013)
- ISSN：1932-7455
文摘
For oxygen reduction reaction (ORR) over alloy electrocatalysts, the understanding of how the atomic arrangement of the metal species in the nanocatalysts is responsible for the catalytic enhancement is challenging for achieving better design and tailoring of nanoalloy catalysts. This paper reports results of an investigation of the atomic structures and the electrocatalytic activities of ternary and binary nanoalloys, aiming at revealing a fundamental insight into the unique atomic-scale structure鈥揺lectrocatalytic activity relationship. PtIrCo catalyst and its binary counterparts (PtCo and PtIr) are chosen as a model system for this study. The effect of thermochemical treatment temperature on the atomic-scale structure of the catalysts was examined as a useful probe to the structure鈥揳ctivity correlation. The structural characterization of the binary and ternary nanoalloy catalysts was performed by combining surface sensitive techniques such as XPS and 3D atomic ordering sensitive techniques such as high-energy X-ray diffraction (HE-XRD) coupled to atomic pair distribution function (PDF) analysis (HE-XRD/PDFs) and computer simulations. The results show that the thermal treatment temperature tunes the nanoalloy鈥檚 atomic and chemical ordering in a different way depending on the chemical composition, leading to differences in the nanoalloy鈥檚 mass and specific activities. A unique structural tunability of the atomic ordering in a platinum鈥搃ridium鈥揷obalt nanoalloy has been revealed for enhancing greatly the electrocatalytic activity toward oxygen reduction reaction, which has significant implication for rational design and nanoengineering of advanced catalysts for electrochemical energy conversion and storage.