Recent progress of electrocatalysts for acidic oxygen evolution reaction

Water electrolysis is presently recognized as one of the most effective and ecological technologies for producing sustainable hydrogen energy. Compared with alkaline electrolyzers, the acidic electrolyzers with proton exchange membranes (PEMs) hold much greater advantages, including high efficiency, few side reactions, and effective suppression of gas crossover. However, the development and application of PEMs water electrolysis is limited by the high theoretical voltage and slow reaction kinetics. Additionally, the fact that many OER catalysts dissolve and corrode rapidly in harsh acidic environments, resulting in reduced catalytic activity. There is an urgent need to find acid-resistant and high activity catalysts to meet the demands of industrial applications of PEMs water electrolysis. In this review, the general mechanism of OER, different kinds of acidic OER catalysts, the design and synthesis strategies are firstly summarized and discussed. The pertinent foundational researches on OER catalyst synthesis and the correlation between catalytic activity and coordination environment are particularly emphasized to provide a detailed comprehension for catalysis at the atomic level. Then, current important issues and viable strategies are proposed to promote the development of acidic OER catalysts.