Interfacial water regulation for water-participating electrocatalytic hydrogenation reactions

Electrocatalytic hydrogenation of abundant feedstocks to value-added products using water as the hydrogen source offers promising alternatives to traditional methods. At the electrode-electrolyte interface, water molecules not only act as active hydrogen sources but also facilitate mass transport via hydrogen-bond networks. The configuration, orientation, and distribution of interfacial water molecules are directly related to the connectivity of the hydrogen-bond network, thereby directly determining the hydrogenation efficiency. A fundamental understanding of interfacial water dynamics and the development of precise modulation strategies are key to advancing electrochemical hydrogenation. This perspective systematically discusses three dominant strategies—namely, manipulating the local electric field, engineering surface modifications/electrolyte additives, and tuning solvated-cation interactions—to regulate the properties of interfacial water and enhance the corresponding hydrogenation performance. Finally, we highlight critical issues for future research aimed at better controlling interfacial water dynamics to enhance the performance of electrocatalytic hydrogenation and other water-participating reactions.