Ultralow-Potential Hydrazine Oxidation for Energy-Saving Hydrogen Production: Regulating Interfacial OH– Dynamics Achieves Fast Dehydrogenation of N2H4 in Alkaline

Abstract Hydrazine-assisted water electrolysis offers a promising energy-saving route for hydrogen production, yet its efficiency is often hindered by competitive adsorption between OH– and N2H4 in alkaline media. Here, we aim to regulate interfacial OH– dynamics to accelerate hydrazine dehydrogenation. A Ru/WO3/NF heterostructure was constructed, in which oxophilic WO3 acts as an OH– buffer to redistribute hydroxyl species away from Ru active sites and create a favorable interfacial microenvironment for N2H4 adsorption and activation. Both experimental measurements and theoretical calculations confirm that this strategy lowers the hydrazine oxidation potential to 0.11 V vs RHE at 400 mA cm–2, delivers a Tafel slope of 26 mV dec–1, and maintains stable operation for 120 h at 200 mA cm–2. When applied in a membrane electrode assembly for hydrazine-assisted overall water splitting, only 0.548 V is required to reach 200 mA cm–2. This work highlights interfacial OH– regulation as a powerful design principle for efficient and practical hydrogen production.