Heterostructured catalysts show outstanding performance in electrochemical reactions owing to their beneficial interfacial properties. However, the rational design of heterostructured catalysts with the desired interfacial properties and charge-transfer characteristics is challenging. Herein, we developed a SrMn3 O6-x -SrMnO3 (SMOx -SMO) heterostructure through epitaxial growth, which demonstrated excellent electrocatalyst performance for the oxygen reduction reaction (ORR). The formation of high-valence Mn3+/4+ is beneficial for promoting a positive shift in the position of the d-band center, thereby optimizing the adsorption and desorption of ORR intermediates on the heterojunction surface and resulting in improved catalytic activity. When SMOx -SMO was applied as an air-electrode catalyst in a rechargeable zinc-air battery, a high output voltage and power density was achieved, with performance comparable to a battery prepared with Pt/C-IrO2 air-electrode catalysts, albeit with much better cycling stability.
Keywords: heterostructures; oxygen reduction reaction; perovskites; zinc-air batteries.
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