Bismuth Substituted Strontium Cobalt Perovskites for Catalyzing Oxygen Evolution [post]

Denis Kuznetsov, Jiayu Peng, Livia Giordano, Yuriy Román-Leshkov, Yang Shao-Horn
2019 unpublished
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 Bi<sub>0.2</sub>Sr<sub>0.8</sub>CoO<sub>3-δ</sub> (δ close to zero) was shown to exhibit record OER specific activity exceeding not only La<sub>x</sub>Sr<sub>1-x</sub>CoO<sub>3-δ</sub> but also charged
more » ... also charged SrCoO<sub>3-δ</sub> (δ close to zero), one of the most active oxide OER catalysts reported so far. The enhanced OER activity of charged Bi<sub>0.2</sub>Sr<sub>0.8</sub>CoO<sub>3-δ</sub> can be attributed to greater hydroxide affinity facilitating the deprotonation of surface bound intermediates due to the presence of strong Lewis acidic A-site Bi<sup>3+</sup> 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.
doi:10.26434/chemrxiv.8851802.v1 fatcat:v4tjbczvmra2folska4o2re7hy