Covalency-reinforced oxygen evolution reaction catalyst

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 Fe(4+)-based quadruple perovskite CaCu(3)Fe(4)O(12) has high activity, which is comparable to or exceeding those of state-of-the-art catalysts such as Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3−δ) and the gold standard RuO(2). The covalent bonding network incorporating multiple Cu(2+) and Fe(4+) transition metal ions significantly enhances the structural stability of CaCu(3)Fe(4)O(12), which is key to achieving highly active long-life catalysts.