Recent Strategies Toward Durable and Ion‐Tolerant Transition Metal‐Based Electrocatalysts in Seawater Electrolysis

ABSTRACT As global energy demand continues to rise, developing sustainable and clean energy technologies has become an urgent priority. Hydrogen production from seawater electrolysis has attracted growing attention as a cost‐effective and sustainable approach due to the abundance of seawater as a feedstock. However, during seawater electrolysis, both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are strongly influenced not only by catalyst activity but also by the complex composition of seawater. In particular, the presence of chloride ions and alkaline‐earth metal salts such as Ca ²⁺ and Mg ²⁺ reduces efficiency compared with freshwater systems, while the competitive chlorine evolution reaction (ClER) compromises oxygen selectivity and accelerates electrode degradation. To address these challenges, designing corrosion‐resistant OER and HER catalysts with high activity and long‐term stability is of great importance. This review provides a comprehensive overview of transition metal‐based catalysts for seawater electrolysis, emphasizing their reaction mechanisms, degradation pathways, and structural instability caused by poor reaction selectivity. Furthermore, we summarize recent advances in improving catalyst durability through electrolyte modification and electrolyzer design optimization. Finally, we outline key material design principles for developing robust anode and cathode catalysts and present prospects for future research. The insights presented here aim to guide the rational design of highly stable, corrosion‐tolerant catalysts for efficient and scalable seawater electrolysis, promoting its practical application in clean energy conversion and storage.