Advanced Approaches toward Efficient Electrocatalysts for Seawater Electrolysis: A Comprehensive Review

Green hydrogen production via direct seawater electrolysis represents a promising and sustainable pathway to reduce reliance on fossil fuels and mitigate carbon emissions, while simultaneously alleviating the pressure on limited freshwater resources. Covering 75% of the earth, seawater holds significant potential for large-scale hydrogen generation. However, its complex composition, particularly the high concentration of chloride ions (Cl-), impacts the performance and durability of electrocatalysts, leading to corrosion, degradation, and competing side reactions. To address these limitations, extensive research has focused recently on developing new strategies to enhance catalyst activity, selectivity, and long-term stability under harsh saline conditions. This review consolidates recent progress in the field, covering fundamental mechanisms, major operational challenges, and emerging approaches aimed at improving the efficiency of next-generation electrocatalysts for seawater electrolysis. Notable advancements include the modulation of the local reaction environment, the rational tuning of catalytic reaction mechanisms, and the regulation of interfacial pH. Additionally, innovative approaches such as light-assisted seawater electrolysis, along with the development of advanced passivation coatings, doped materials, and novel catalyst designs, are thoroughly examined. By presenting a comprehensive overview of these developments, this review aims to facilitate continued innovation in the pursuit of practical and scalable solutions for green hydrogen production from seawater. Finally, a thorough and critical discussion is presented in the last section of the review to assess the feasibility and scalability of these strategies.