Proton Exchange Membrane Water Splitting: Advances in Electrode Structure and Mass‐Charge Transport Optimization

Abstract Proton exchange membrane water electrolysis (PEMWE) represents a promising technology for renewable hydrogen production. However, the large‐scale commercialization of PEMWE faces challenges due to the need for acid oxygen evolution reaction (OER) catalysts with long‐term stability and corrosion‐resistant membrane electrode assemblies (MEA). This review thoroughly examines the deactivation mechanisms of acidic OER and crucial factors affecting assembly instability in complex reaction environments, including catalyst degradation, dynamic behavior at the MEA triple‐phase boundary, and equipment failures. Targeted solutions are proposed, including catalyst improvements, optimized MEA designs, and operational strategies. Finally, the review highlights perspectives on strict activity/stability evaluation standards, in situ/operando characteristics, and practical electrolyzer optimization. These insights emphasize the interrelationship between catalysts, MEAs, activity, and stability, offering new guidance for accelerating the commercialization of PEMWE catalysts and systems.