Direct seawater electrolysis for hydrogen production

Abstract

Direct seawater electrolysis (DSE) is a sustainable technology for green hydrogen production. However, implementing this technology remains highly challenging owing to the poor catalytic activity and limited lifetime that result from corrosion, chlorine-related side reactions and metal precipitates. Here, we provide a comprehensive overview and critical discussion of current challenges and possible solutions for DSE in terms of the seawater electrolyte, catalysts, membranes and electrolysers. We first discuss challenges and opportunities stemming from impurity ions in seawater and explore potential seawater treatment solutions to improve DSE performance. We then summarize and propose effective strategies for designing efficient hydrogen and oxygen evolution reaction catalysts for DSE. Next, recent progress in, and challenges for, membranes used in DSE are presented, including analysis of the membrane degradation mechanisms and possible mitigation strategies. We also critically review and discuss the advantages and challenges of both conventional and novel electrolysers for DSE. Importantly, to guide future research, we emphasize how to further optimize strategies and solutions to tackle degradation and corrosion in DSE under real-world operating conditions. Finally, we discuss future challenges and prospects for the large-scale application of DSE technology.