Electronic and Structural Determinants of Activity and Stability in Noble Metal OER Catalysis

ABSTRACT Electrochemical water splitting, particularly via proton exchange membrane (PEM) electrolyzers, is a pivotal strategy for converting renewable energy into high‐purity hydrogen fuel. However, the oxygen evolution reaction (OER) at the anode remains a critical bottleneck due to its sluggish kinetics and the harsh acidic environment. Despite the development of numerous electrocatalyst systems, only noble metal‐based materials, primarily Ir and Ru, demonstrate satisfactory activity and durability in practical applications. The reliance on scarce and expensive metals underscores the urgent need for innovative catalyst design strategies that balance activity, stability, and cost. This review explores recent progress in noble metal‐based OER electrocatalysts, emphasizing electronic structure tuning that influences performance. The review begins with core concepts of OER reaction mechanisms and performance metrics. Then, it examines the critical topics of catalyst electronic engineering, crystallographic control, lattice modification, and dynamic surface. The review concludes by discussing broader challenges such as the need for standardized testing, long‐term durability benchmarks, and industry‐relevant metrics and highlights the importance of interdisciplinary collaboration to advance sustainable, scalable OER technologies for green hydrogen production.