Constructing Ru-O-TM Bridge in NiFe-LDH Enables High Current Hydrazine-assisted H₂ Production

Hydrazine oxidation-assisted water splitting is a critical technology to tackle the high energy consumption in large-scale H₂ production. Ru-based electrocatalysts hold promise for synergetic hydrogen reduction (HER) and hydrazine oxidation (HzOR) catalysis but are hindered by excessive superficial adsorption of reactant intermediate. Herein, this work designs Ru cluster anchoring on NiFe-LDH (denoted as Ru_c/NiFe-LDH), which effectively enhances the intermediate adsorption capacity of Ru by constructing Ru─O─Ni/Fe bridges. Notably, it achieves an industrial current density of 1 A cm^-2 at an unprecedentedly low voltage of 0.43 V, saving 3.94 kWh m^-3 _H2 in energy, and exhibits remarkable stability over 120 h at a high current density of 5 A cm^-2. Advanced characterizations and theoretical calculation reveal that the presence of Ru─O─Ni/Fe bridges widens the d-band width (W_d) of the Ru cluster, leading to a lower d-band center and higher electron occupation on antibonding orbitals, thereby facilitating moderate adsorption energy and enhanced catalytic activity of Ru.