Anode design principles for efficient seawater electrolysis and inhibition of chloride oxidation

Abstract

At present, seawater electrolysis powered by renewable energy stands as a crucial method for the industrial production of hydrogen. Given the abundance of seawater and its inherently high conductivity, seawater electrolysis earns an increasing interest. Nonetheless, challenges remain, such as the competitive chloride oxidation reaction (COR) caused by chloride ions (Cl^‒) and the corrosion of active sites, which hinder the industrial seawater electrolysis. In this review, we initially outline four design strategies aimed at avoiding the occurrence of COR: designing selective oxygen evolution reaction (OER) active sites, anti-corrosion strategies, small molecules oxidize reaction (SMOR) and adjusting electrolyte. Specifically, we compile approaches to enhance the OER selectivity and corrosion resistance in seawater electrolysis, including introducing anion buffer layer. Subsequently, we categorize reported OER catalysts based on their composition and summarize the mechanism underlying their high activity and stability. In conclusion, we address the future challenges and prospects of industrializing seawater electrolysis.