Seawater Electrolysis: The Synergistic Trio‐pillar Strategy Against Hurdles

Addressing the crucial energy‐water (EW) nexus, direct seawater electrolysis (DSE) emerges as a sustainable route for one‐step green hydrogen generation, effectively decoupling energy conversion from freshwater scarcity. This approach sidesteps the high energy consumption and complexity associated with desalination. However, the challenges posed by seawater's intricate chemistry and corrosiveness include electrode degradation, competitive chlorine evolution reaction (ClER), salt precipitation, and biofouling, which negatively affect the electrolyzers' performance metrics. This review delves into the electrocatalysis principles and DSE hurdles, highlighting recent advanced electrode materials and catalyst designs aimed at enhancing selectivity, corrosion resistance, and fouling prevention. It also evaluates current innovations in the regulation of electrolyte chemistry and device development for high‐performance energy storage. And in this regard, a system‐level synergistic trio‐pillar strategy is suggested, integrating progress in electrolyte engineering, electrode design, and electrolyzer configuration, along with a multidisciplinary research roadmap that combines materials science, system engineering, and electrochemical technology to achieve commercially viable seawater splitting at the future gigawatt scale. Furthermore, a purposeful perspective shift toward the chlorine economy is proposed, transforming chlorine from a parasitic by‐product into a valuable co‐product alongside freshwater co‐generation. Ultimately, this work provides clear guidance for next‐generation renewable energy technology.