Application of microenvironment regulation in seawater electrolysis

Water scarcity remains a major constraint for sustainable hydrogen production via water electrolysis, making direct seawater electrolysis (DSE) an attractive route toward large-scale hydrogen production. However, complex interferents in real seawater, particularly Cl − , Mg 2+ and Ca 2+ , readily induce competing chlorine evolution, electrode corrosion, and cathodic scaling, severely limiting the long-term operation and industrialization of DSE. This review systematically examines interfacial microenvironment regulation, operando characterization, and theoretical simulations in DSE. Beyond the conventional catalyst-centered paradigm, this review establish an interfacial microenvironment perspective to elucidate how local pH regulation, interfacial hydrogen-bond network reconstruction, and multiscale bubble desorption dynamics jointly reshape ion transport, interfacial water structure, and reaction kinetics. These strategies enable the construction of ion-repulsive barriers while alleviating mass-transfer limitations and local activity decay under high current densities, thereby addressing the dual challenges of reaction kinetics and long-term stability. Finally, we discuss the limitations of transient interfacial characterization and highlight future opportunities for industrial-scale microenvironment engineering.