Prevention of Cathodic Precipitation in Seawater Electrolysis: From Mechanistic Insights to Advanced Mitigation Strategies

ABSTRACT The global demand for clean, sustainable, and scalable energy solutions has positioned hydrogen as a key alternative fuel. Seawater electrolysis offers a promising pathway for green hydrogen production. However, the process faces significant challenges, particularly the formation of insoluble precipitates such as CaCO 3 and Mg(OH) 2 , which hinder the efficiency, durability, and scalability of the hydrogen evolution reaction (HER) from seawater. This review not only systematically summarizes recent progress but also proposes a synergistic design paradigm (materials‐interface‐system) for cathode protection. By bridging fundamental mechanisms to scalable solutions, we aim to provide a definitive guide for accelerating the development of reliable, sustainable seawater electrolysis systems, ultimately unlocking the vast potential of the ocean for a green hydrogen economy.