A Review of Hydrogen Production via Seawater Electrolysis: Current Status and Challenges

Seawater electrolysis represents a promising green energy technology with significant potential for efficient energy conversion. This study provides an in-depth examination of the key scientific challenges inherent in the seawater-electrolysis process and their potential solutions. Initially, it analyzes the potential issues of precipitation and aggregation at the cathode during hydrogen evolution, proposing strategies such as self-cleaning cathodes and precipitate removal to ensure cathode stability in seawater electrolysis. Subsequently, it addresses the corrosion challenges faced by anode catalysts in seawater, introducing several anti-corrosion strategies to enhance anode stability, including substrate treatments such as sulfidation, phosphidation, selenidation, and LDH (layered double hydroxide) anion intercalation. Additionally, this study explores the role of regulating the electrode surface microenvironment and forming unique coordination environments for active atoms to enhance seawater electrolysis performance. Regulating the surface microenvironment provides a novel approach to mitigating seawater corrosion. Contrary to the traditional understanding that chloride ions accelerate anode corrosion, certain catalysts benefit from the unique coordination environment of chloride ions on the catalyst surface, potentially enhancing oxygen evolution reaction (OER) performance. Lastly, this study presents the latest advancements in the industrialization of seawater electrolysis, including the in situ electrolysis of undiluted seawater and the implementation of three-chamber dual anion membranes coupled with circulating electrolyte systems. The prospects of seawater electrolysis are also explored.