Low-cost electrocatalysts for acidic oxygen evolution reaction: Advances, strategies, and challenges

Proton exchange membrane water electrolysis (PEMWE) has emerged as a promising technology for converting renewable energy into hydrogen. However, current anode catalysts in PEMWE predominantly rely on noble metals, particularly iridium (Ir) and ruthenium (Ru). The high cost and scarcity of these materials limit the widespread deployment of PEMWE for green hydrogen production. This review discusses compositional tuning strategies, including heteroatom doping and alloying, as well as structural optimization approaches involving advanced supports and morphology control. Additionally, emerging nonprecious metal alternatives are examined. Key mechanisms, such as the adsorbate evolution mechanism (AEM) and the lattice oxygen oxidation mechanism (LOM), are analyzed to guide rational catalyst design. By focusing on strategies for developing low-cost acidic oxygen evolution reaction (OER) electrocatalysts, this review addresses the critical need to reduce precious metal content. Finally, we conclude with an outlook on key scientific challenges and future directions in the field.