Cooperative Ni(Co)‐Ru‐P Sites Activate Dehydrogenation for Hydrazine Oxidation Assisting Self‐powered H2 Production

Abstract Water electrolysis for H 2 production is restricted by the sluggish oxygen evolution reaction (OER). Using the thermodynamically more favorable hydrazine oxidation reaction (HzOR) to replace OER has attracted ever‐growing attention. Herein, we report a twisted NiCoP nanowire array immobilized with Ru single atoms (Ru 1 −NiCoP) as superior bifunctional electrocatalyst toward both HzOR and hydrogen evolution reaction (HER), realizing an ultralow working potential of −60 mV and overpotential of 32 mV for a current density of 10 mA cm −2 , respectively. Inspiringly, two‐electrode electrolyzer based on overall hydrazine splitting (OHzS) demonstrates outstanding activity with a record‐high current density of 522 mA cm −2 at cell voltage of 0.3 V. DFT calculations elucidate the cooperative Ni(Co)−Ru−P sites in Ru 1 −NiCoP optimize H* adsorption, and enhance adsorption of *N 2 H 2 to significantly lower the energy barrier for hydrazine dehydrogenation. Moreover, a self‐powered H 2 production system utilizing OHzS device driven by direct hydrazine fuel cell (DHzFC) achieve a satisfactory rate of 24.0 mol h −1 m −2 .