Core–Shell Nanostructured Cobalt–Platinum Electrocatalysts with Enhanced Durability

Journal Article · Tue Nov 28 00:00:00 EST 2017 · ACS Catalysis

DOI:https://doi.org/10.1021/acscatal.7b02501· OSTI ID:1485431

Wang, Lei ^[1]; Gao, Wenpei ^[2]; Liu, Zhenyu ^[3]; Zeng, Zhenhua ^[4]; Liu, Yifan ^[1]; Giroux, Michael ^[1]; Chi, Miaofang  ^[5]; Wang, Guofeng  ^[3]; Greeley, Jeffrey  ^[4]; Pan, Xiaoqing  ^[6]; Wang, Chao  ^[1]

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1. Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
2. Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, United States
3. Department of Mechanical Engineering &, Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
4. Davison School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
5. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
6. Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, United States; Department of Physics and Astronomy, University of California, Irvine, California 92697, United States

Pt-bimetallic alloys involving 3d transition metals (Co, Ni, etc.) are promising electrocatalysts for the oxygen reduction reaction (ORR). Despite the enhanced catalytic activity versus Pt, the electrocatalytic performance of Pt-bimetallic catalysts is however limited by the lack of long-term durability, primarily due to the leaching of the non-noble element under harsh electrochemical conditions. Our study shows that the core–shell nanostructure comprising a Pt shell and a cobalt core (denoted as Co@Pt) could overcome this limitation, demonstrating ~10 times improvement in catalytic activity versus commercial Pt catalysts and no more than 13% of loss after 30000 potential cycles. The evolutions of nanoscale and surface structures over the course of extensive potential cycling were followed by combining electron microscopic elemental mapping and electrochemical studies of CO stripping. Atomistic simulations and density functional theory calculations suggest that the core–shell nanostructure could protect the non-noble cobalt from leaching under the “electrochemical annealing” conditions while maintaining the beneficial mechanisms of bimetallic systems for catalytic activity enhancement.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division; National Science Foundation (NSF)
• OSTI ID: 1485431
• Journal Information: ACS Catalysis, Vol. 8, Issue 1; ISSN 2155-5435
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English