Cation-modulated hydrogen-bond networks in electrochemical NO 3 − reduction

Electrochemical nitrate reduction (NO 3 RR) represents an environmentally sound pathway for converting nitrate ions (NO − 3 ) to ammonia in wastewater. However, the mechanism governing NO − 3 hydrogenation under altered liquid-phase conditions remains poorly understood. This study enhances the reactivity of CeO 2 toward nitrate hydrogenation by loading it with transition metals and further modifying the composition of alkali metal cations in the electrolyte. This approach regulates the continuity of both interfacial water and hydrogen-bond networks, facilitating NO − 3 -proton coupling and thereby boosting NO 3 RR reactivity. Furthermore, the incorporation of diverse surfactants into the electrolyte confirms that alterations in the liquid-phase environment influence interfacial water distribution, ultimately improving NO 3 RR reactivity. This study deepens our understanding of interfacial water’s role in NO 3 RR, providing a theoretical basis for developing more efficient electrocatalysts.