Design strategies for cost-effective high-performance electrocatalysts in seawater electrolysis to produce hydrogen

Direct electrolysis of seawater to produce green hydrogen is a more environmentally friendly process than freshwater electrolysis. The renewable energy sector exhibits tremendous interest in practical seawater electrolysis techniques due to its substantial capacity to mitigate the need for freshwater consumption. With the low catalytic efficiency of the current seawater splitting process and the poor reliability of its operation, the process suffers from severe corrosion caused by chloride ions, as well as anodic competition between oxygen evolution and chlorine oxidation reactions. This review provides an overview of the latest electrocatalyst developments for promoting selectivity and stability in seawater electrolysis. Using the characterization and simulation results, as well as active machine learning, advanced electrocatalytic materials can be designed and developed, a research direction that will become increasingly important in the future. A variety of strategies are discussed in detail for designing advanced electrocatalysts in seawater electrolysis, including the surface protective layer, structural regulation by heteroatom doping and vacancies, porous structure, core-shell construction, and 3D hetero-structure construction to hinder chlorine evolution reactions. Finally, future perspectives and challenges for green hydrogen production from seawater electrolysis are also described.