Seawater electrolysis: Unlocking a new path for hydrogen production

The hydrogen economy concept is an emerging future scenario designed to address climate change and secure energy for planet Earth, in which water electrolysis combined with renewable energy sources can produce abundant amounts of hydrogen. In recent years, water electrolyzers have been developed for industrial operational conditions. However, there is a significant strain on freshwater when hydrogen is produced on a large scale. Direct seawater electrolysis can rely on freshwater to produce hydrogen on a large scale. However, seawater electrolysis is very challenging due to the presence of chlorine chemistry, sluggish kinetics, and impurities, which make it more difficult. Over the years, immense efforts have been devoted to developing electrocatalysts for seawater electrolysis. The article examines general principles and various electrocatalysts to gain a deeper understanding of the current achievements in catalysts for seawater electrolysis and their prospects. Afterward, novel strategies are suggested for designing effective electrocatalysts, including protective layers for the cathode and anode in seawater electrolysis. Lastly, emerging hybrid seawater electrolysis and electrolyzer technology provide a workable alternative. This review provides the future fields of study that have the potential to be rational extensions of electrocatalyst development toward practical applications.