Recent Studies on Bifunctional Perovskite Electrocatalysts in Oxygen Evolution, Oxygen Reduction, and Hydrogen Evolution Reactions under Alkaline Electrolyte

The bifunctional electrocatalyst plays a pivotal role in renewable-energy technologies metal-air-batteries and water electrolysis. The advantage of the alkaline environment allows such technologies to utilize several low-cost and efficient non-noble transition metal oxides. Particularly, perovskite oxides (POs) of high intrinsic catalytic activity and tunable crystal structures have shown exceptional bifunctionality characteristics in oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)/OER in the aforementioned system. This review focuses on the recent advancement of POs electrocatalyst in the fundamental reaction mechanism and the key factors for the catalytic improvement. The recent issues of POs related to the catalytic inhibitor and their future directions have been comprehended.