Mitigating chlorine-induced damage: Advances in chlorine corrosion mechanisms and anti-corrosion strategies for anode catalysts in hydrogen production via seawater electrolysis

Seawater electrolysis has been explored as a viable and sustainable method for green hydrogen production in regions characterized by freshwater scarcity but abundant renewable energy resources. However, the high concentration of chlorine ions (Cl−) in seawater leads to severe corrosion of metallic electrodes, which significantly challenges the stability of electrode catalysts in seawater electrolysis. Owing to the Cl− corrosion and the competitive oxygen/chlorine evolution reactions, the design of durable and active anode catalysts is key to achieving practical seawater electrolysis. To address this challenge, this review systematically analyzes the chlorine-induced corrosion mechanisms of anode catalysts, evaluates various anticorrosion strategies, and explores future prospects for enhancing anode durability. Three mainstream anticorrosion strategies are summarized and assessed for their effectiveness in mitigating the chlorine-induced damage to anode catalysts: the physical surface coatings, electrostatic repulsion, and Cl− adsorption regulation. In addition, some emerging strategies are further introduced to highlight the future trends of state-of-the-art techniques for seawater electrolysis. This review aims to provide novel insights and practical guidance for developing more stable and efficient anode catalysts for hydrogen production via seawater electrolysis.