Seawater Electrolysis: Challenges, Recent Advances, and Future Perspectives

Driven by the advantages of hydrogen energy, such as environmental protection and high energy density, the market has an urgent demand for hydrogen energy. Currently, the primary methods for hydrogen production mainly include hydrogen generation from fossil fuels, industrial by-products, and water electrolysis. Seawater electrolysis for hydrogen production, due to its advantages of cleanliness, environmental protection, and ease of integration with renewable energy sources, is considered the most promising method for hydrogen production. However, seawater electrolysis faces challenges such as the reduction of hydrogen production efficiency due to impurities in seawater, as well as high costs associated with system construction and operation. Therefore, it is particularly necessary to summarize optimization strategies for seawater electrolysis for hydrogen production to promote the development of this field. In this review, the current situation of hydrogen production by seawater electrolysis is first reviewed. Subsequently, the challenges faced by seawater electrolysis for hydrogen production are categorized and summarized, and solutions to these challenges are discussed in detail. Following this, an overview of an in situ large-scale direct electrolysis hydrogen production system at sea is presented. Last but not least, suggestions and prospects for the development of seawater electrolysis for hydrogen production are provided. Based on exploring the challenges of hydrogen production by seawater electrolysis, this review summarizes various strategies to improve the efficiency of seawater electrolysis, including the integration of osmotic technology with seawater indirect electrolysis, reduction of the impact of impurity ions such as Cl-, Mg2+, Ca2+, and microorganisms, the design of bifunctional catalysts, and the application of large-scale in situ hydrogen production at sea. image