Principles of Designing Electrocatalyst to Boost Reactivity for Seawater Splitting

Abstract Directly seawater electrolysis would be a transformative technology for large‐scale carbon‐neutral hydrogenproduction without relying on pure water. However, current seawater splitting is challenged by detrimental chlorine chemistry, the sluggish kinetics, and the existence of impurities/precipitates, making it more difficult than pure water splitting. So far, tremendous efforts have been made to develop electrocatalysts to boost the electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities for seawater‐based electrolyzers. To get further insights into the current achievements and future perspectives of the catalysts for seawater electrolysis, general principles are summarized for a comprehensive optimization, ranging from active sites, electrochemical interface, to electron transfer path, to fully improve electrocatalytic performance for seawater electrolysis. Then, aiming at the different challenges of the cathode and anode for seawater electrolysis, unique strategies to design effective cathodic and anodic catalysts, such pH design criterion, selective HER/OER, and Cl − blocking layers, are discussed, respectively. Also, several future fields which are worthy for further exploration as rational extensions of developing electrocatalysts toward practical applications are put forward.