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

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.