The formation of unsaturated IrO<sub>x</sub> in SrIrO<sub>3</sub> by cobalt-doping for acidic oxygen evolution reaction.

Zhao, Jia-Wei; Yue, Kaihang; Zhang, Hong; Wei, Shu-Yin; Zhu, Jiawei; Wang, Dongdong; Chen, Junze; Fominski, Vyacheslav Yu et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Electrocatalytic water splitting is a promising route for sustainable hydrogen production. However, the high overpotential of the anodic oxygen evolution reaction poses significant challenge. SrIrO<sub>3</sub>-based perovskite-type catalysts have shown great potential for acidic oxygen evolution reaction, but the origins of their high activity are still unclear. Herein, we develop a Co-doped SrIrO<sub>3</sub> system to enhance oxygen evolution reaction activity and elucidate the origin of catalytic activity. In situ experiments reveal Co activates surface lattice oxygen, rapidly exposing IrO<sub>x</sub> active sites, while bulk Co doping optimizes the adsorbate binding energy of IrO<sub>x</sub>. The Co-doped SrIrO<sub>3</sub> demonstrates high oxygen evolution reaction electrocatalytic activity, markedly surpassing the commercial IrO<sub>2</sub> catalysts in both conventional electrolyzer and proton exchange membrane water electrolyzer.