Polyoxometalate-derived N@Mo ₂ C/V ₂ O ₃ cluster heterostructure for accelerated alkaline hydrogen evolution reaction

The hydrogen evolution reaction (HER) in alkaline water electrolysis is fundamentally limited by the high energy barrier of water dissociation. Herein, we developed a self-supported nitrogen doped molybdenum carbides and vanadium oxides cluster heterostructures (N@Mo₂C/V₂O₃) on carbon fiber paper using organoimido-derivatized molybdovanadate nanoclusters as precursors. Both experiments and theoretical calculations demonstrated that the engineered cluster heterointerface significantly reduces the energy barrier of the rate-determining step, accelerating the reaction kinetics. Moreover, the V₂O₃ served as a co-catalyst to enhance the hydrophilicity and facilitate hydrogen desorption of N@Mo₂C. The optimized N@Mo₂C/V₂O₃ catalyst exhibits exceptional performance, achieving current density of 300 mA·cm^-2 at an overpotential of merely 191 mV and demonstrating stability over 400 hours of continuous operation. When integrated into an alkaline water electrolyzer (AWE), the system requires only 1.94 V to deliver an industrial-relevant current density of 500 mA·cm^-2, surpassing commercial platinum-carbon catalysts. These findings offer new perspectives and valuable insights into the development of efficient, stable, and economical noble-metal-free electrocatalysts for green hydrogen production.