Decoding heterogeneous electrocatalysts for acidic oxygen evolution: mechanisms, rational design and AI acceleration.

Proton exchange membrane water electrolyzers (PEMWEs) are positioned as a transformative technology for renewable energy conversion and storage systems. The acidic oxygen evolution reaction (AOER), serving as the pivotal half-reaction governing overall efficiency, operational stability and system cost in water electrolysis, has become a focal point of contemporary electrochemical research. In this Review, we comprehensively summarize the recent advancements in both noble metal-based (Ir and Ru) and non-noble-metal-based (Mn and Co) heterogeneous electrocatalysts (HEs) for the AOER. The analysis commences with fundamental AOER mechanisms and the key factors that influence them, elucidating critical structure-activity relationships essential for rational catalyst engineering. Subsequently, we systematically evaluate state-of-the-art design strategies and corresponding breakthroughs in catalyst development, followed by a forward-looking perspective on the emergence and application of AI for science in the AOER. This review provides valuable guidance for the design of next-generation HEs for the AOER, ultimately aiming to bridge the gap between laboratory-scale achievements and industrial implementation of PEMWE technologies.