Covalency-reinforced oxygen evolution reaction catalyst

Abstract

The oxygen evolution reaction that occurs during water oxidation is of considerable importance as an essential energy conversion reaction for rechargeable metal-air batteries and direct solar water splitting. Cost-efficient ABO 3 perovskites have been studied extensively because of their high activity for the oxygen evolution reaction; however, they lack stability, and an effective solution to this problem has not yet been demonstrated. Here we report that the Fe4+ -based quadruple perovskite CaCu3 Fe4 O12 has high activity, which is comparable to or exceeding those of state-of-the-art catalysts such as Ba0.5 Sr0.5 Co0.8 Fe0.2 O3-δ and the gold standard RuO2. The covalent bonding network incorporating multiple Cu2+ and Fe4+ transition metal ions significantly enhances the structural stability of CaCu3 Fe4 O12, which is key to achieving highly active long-life catalysts.