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Bismuth Substituted Strontium Cobalt Perovskites for Catalyzing Oxygen Evolution

preprint
submitted on 10.07.2019 and posted on 11.07.2019 by Denis Kuznetsov, Jiayu Peng, Livia Giordano, Yuriy Román-Leshkov, Yang Shao-Horn
In this study, we employ the strategy of substitution with more electronegative/acidic A-site ions in the cobalt perovskites to alter O 2p-band center, surface hydroxide affinity, and oxygen evolution reaction (OER) activity and stability in the basic electrolyte. Galvanostatically charged Bi0.2Sr0.8CoO3-δ (δ close to zero) was shown to exhibit record OER specific activity exceeding not only LaxSr1-xCoO3-δ but also charged SrCoO3-δ (δ close to zero), one of the most active oxide OER catalysts reported so far. The enhanced OER activity of charged Bi0.2Sr0.8CoO3-δ can be attributed to greater hydroxide affinity facilitating the deprotonation of surface bound intermediates due to the presence of strong Lewis acidic A-site Bi3+ ions, while the high stability can result from lowered O 2p-band center relative to the Fermi level. This work provides a novel example in the rational design of highly active oxide catalysts for OER by leveraging the inductive effect.

Funding

Office of Science of the U.S. Department of Energy, contract No. DE-AC02-05CH11231

National Science Foundation, grant number ACI-1548562

National Science Foundation, award number DMR-1419807

History

Email Address of Submitting Author

denisk@ethz.ch

Institution

ETH Zurich

Country

Switzerland

ORCID For Submitting Author

0000-0002-6925-2367

Declaration of Conflict of Interest

No conflicts to declare.

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