Direct seawater electrolysis: Breaking the dependency on noble metal-based electrocatalysts

The scarcity of freshwater in renewable energy sources has prompted research into direct seawater electrolysis to generate carbon-neutral hydrogen. While current approaches rely heavily on precious metal-based electrocatalysts, the complex composition of seawater presents significant challenges including competitive chlorine evolution reactions, low catalytic efficiency, and electrode corrosion, necessitating technological breakthroughs for practical direct seawater electrolysis. In this review, we discuss the fundamental principles, key challenges, and recent advances in the rational design of electrocatalysts for direct seawater electrolysis. In particular, we categorize state-of-the-art strategies for designing noble metal-free electrocatalysts tailored to the oxygen evolution reaction and hydrogen evolution reaction in natural seawater. We then, put forward an outlook on future directions, emphasizing the need for durable and efficient electrocatalysts to enhance the techno-economic viability of this emerging field. This review provides perspectives that support the advancement of seawater electrolysis toward sustainable energy conversion and environmental protection.