Towards chlorine-tolerant seawater electrolysis: anode electrocatalysts, electrolyte, and system design strategies

Seawater electrolysis (SWE) is a reusable and convenient avenue of producing hydrogen, offering a promising solution to the energy crisis and global warming. However, poor electrolytic efficiency and irreversible corrosion caused by high concentrations of chlorine severely hinders the commercialization of SWE. To address the above challenges, numerous strategies have been proposed in recent years, involving theoretical innovations, directional catalyst design and electrolyser modification. Herein, we provide a systematic summary of the chlorine-related challenges and solutions encountered in SWE. The chlorine-related theoretical knowledge and challenges in the SWE systems are first emphasized. Subsequently, we introduce multiple anodic chloride suppression strategies from three aspects, including directional regulation of oxygen evolution catalysts, optimization of electrolyte compositions, and ingenious upgrades of electrolytic cells. Finally, we explore the future challenges and development directions for the large-scale application of SWE technology. This review provides an in-depth analysis of the chlorine-related challenges encountered in the industrialization of SWE, aiming to accelerate the advancement of this technology toward practical applications.