Electrocatalysts for acidic oxygen evolution reaction: Achievements and perspectives

Developing efficient electrocatalysts toward acidic oxygen evolution reaction (AOER) is of vital significance in proton exchange membrane (PEM) water electrolysis, which is a promising technique to tackle the approaching energy crisis by supplying high-purity hydrogen. In this work, we first present a general introduction to the AOER mechanism as well as the most important parameters in evaluation of the catalytic performances of catalysts. Fruitful achievements of noble metal-based catalysts (e.g., metals, alloys, and oxides) and noble metal-free catalysts (e.g., transition metal oxides, chalcogenides, and metal-free materials) are fully described, with an emphasis on advanced strategies of catalyst modification/engineering, structure-catalysis correlations, and evolution of catalyst structures and surface chemistry under operational conditions. The representative electrocatalysts are benchmarked based on their catalytic performances. Finally, the challenges are summarized and future opportunities are directed for the rational design of AOER catalysts toward sustainable fuel production.