Perovskite-Based Catalysts for the Oxygen Evolution Reaction: Synthesis, Device Relevant Performance, and Scale-Up Strategies.

Perovskite-based oxides are promising electrocatalysts for the oxygen evolution reaction due to their flexible composition, tunable electronic structure, and robust nature. However, their activity and durability in proton exchange membrane (PEM)-relevant acidic conditions are not fully understood, limiting their use in water electrolyzers. This review critically discusses recent advances in perovskite-based electrocatalysts, covering design, synthesis strategies, morphological engineering, reaction mechanisms, and degradation pathways. Fundamental design principles based on A-/B-site engineering, defect chemistry, metal-oxygen covalency, active-site optimization, and controlled surface reconstruction are discussed together with emerging oxide pathway mechanisms. Particular emphasis is placed on bridging fundamental electrochemical studies with practical implementation through membrane electrode assembly design, catalyst-layer optimization, in situ evaluation, and realistic performance benchmarking. Finally, current challenges associated with standardization, scalability, and industrial implementation are highlighted, and future research directions for developing durable, low-PGM perovskite electrocatalysts for PEM water electrolysis are outlined.