Recent Advances in Nano‐Microstructured Catalysts for Electrochemical Seawater Electrocatalysis

ABSTRACT Seawater electrocatalysis presents a promising route for sustainable hydrogen production and marine resource valorization. However, its practical implementation faces formidable hurdles from complex ionic matrices, parasitic side reactions, and catalyst degradation, particularly in chloride‐rich environments. This Review comprehensively surveys the latest advances in nano‐ and micro‐structured electrocatalysts engineered for robust performance in both natural and simulated seawater systems. We systematically analyze the key physicochemical challenges arising from multicomponent electrolytes and summarize rational catalyst design strategies aimed at improving activity, selectivity, and durability under realistic conditions. Reaction‐specific principles and mechanistic insights are discussed for the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and urea oxidation reaction, highlighting how catalyst structure and interfacial regulation govern performance in complex media. Furthermore, recent progress in theoretical modeling, in situ/operando characterization, and emerging machine‐learning‐assisted approaches is summarized to illustrate how advanced methodologies enable predictive catalyst design. Finally, remaining challenges and future perspectives toward scalable and industrially viable seawater electrocatalysis technologies are outlined.