Engineered B-site high-entropy perovskite oxide catalyst for oxygen evolution reaction

Efficient and durable oxygen evolution reaction (OER) electrocatalysts are critical for advancing rechargeable zinc-air batteries (ZABs). Here, we present a B-site high-entropy perovskite oxide, La(CrMnFeCoNi)O 3 , synthesized via a rapid microwave-assisted method. The incorporation of five equimolar transition metals at the B-site generates high configurational entropy, stabilizing the perovskite lattice and tuning its electronic structure. This catalyst delivers an overpotential of 316 mV at 10 mA cm −2 , a Tafel slope of 56.83 mV dec −1 , and exceptional durability over 100 h of continuous operation. Mechanistic studies combined with density functional theory calculations reveal that the OER proceeds predominantly through the lattice oxygen mechanism, enabling faster oxygen exchange kinetics than the conventional adsorbate evolution mechanism. Integrated into a ZAB as the air cathode, the material achieves a high peak power density and long-term cycling stability, demonstrating strong promise for next-generation metal-air energy systems. • B-site high-entropy perovskite oxide La(CrMnFeCoNi)O 3 , synthesized via a rapid microwave-assisted method. • Mechanistic studies experiments, in situ measurements, DFT calculations reveal that the OER proceeds predominantly through the lattice oxygen mechanism. • When employed as the air cathode in a ZAB, delivers a high open-circuit voltage, impressive specific capacity, and exceptional cycling stability.