Reinforced electron metal-support interaction of Ru/MoC-Mo2C@NC heterogeneous electrocatalysts facilitating both water dissociation and reverse hydrogen spillover for boosted alkaline hydrogen evolution

While alkaline water electrolysis represents a highly promising and sustainable pathway for hydrogen production, its widespread application is hindered by the sluggish kinetics of the hydrogen evolution reaction (HER) due to a large energy barrier for water dissociation. In this work, a heterogeneous electrocatalyst of Ru/MoC-Mo 2 C@NC was prepared by uniformly embedding ruthenium nanoparticles within a nitrogen-doped carbon matrix hosting MoC-Mo 2 C heterojunctions. (MoC-Mo 2 C@NC). Electrochemical experimental results demonstrate the remarkably boosted HER catalytic performance of Ru/MoC-Mo 2 C@NC compared with Ru/NC, Ru/MoC@NC and Ru/Mo 2 C@NC by presenting the lowest overpotential of 18.5 mV at 10 mA cm −2 and Tafel slope of 61.71 mV·dec −1 , along with superior intrinsic activity and mass specific activity. Density-functional theory calculations further reveal that the enhanced electronic metal-support interaction (EMSI) between Ru sites and the MoC-Mo 2 C@NC support in Ru/MoC-Mo 2 C@NC induces significant charge redistribution and interface charge accumulation in Ru/MoC-Mo 2 C@NC, thereby optimizing water dissociation energy barrier and hydrogen adsorption free energy (ΔG H∗ ). Meanwhile, this reinforced EMSI facilitates efficient reverse hydrogen spillover at the Ru/MoC-Mo 2 C@NC interface, which further favors water dissociation on Mo sites and hydrogen desorption on Ru sites of Ru/MoC-Mo 2 C@NC. These regulating effects collectively accelerate the hydrogen intermediate transport and enhance the overall HER kinetics. This work provides valuable insights into enhanced electronic metal-support interaction on a heterostructure catalytic system optimizing both water dissociation and reverse hydrogen spillover for designing highly efficient water electrolysis catalysts.