Stepwise Acceleration of Water Dissociation and Hydrogen Spillover for Enhanced Overall Alkaline Hydrogen Evolution

High Resolution Image Download MS PowerPoint Slide Improving the overall kinetics of the alkaline hydrogen evolution reaction (HER) is crucial for practical applications such as anion exchange membrane water electrolysis (AEMWE). However, the overall catalytic efficiency remains limited because most existing strategies focus only one elementary step, either water dissociation or hydrogen adsorption. Herein, we propose an auxiliary-driving strategy by incorporating VO 2 around Ru active sites to consecutively optimize Volmer and Heyrovsky steps. The formation of V–O–Ru conjugated π-bonds promotes water dissociation by dynamically modulating the electronic structure. Meanwhile, reversible hydrogen spillover optimizes the hydrogen adsorption free energy (Δ G H* ), eventually positioning the catalyst within the optimal region of the two-dimensional microkinetic volcano model. This approach delivers an overpotential of 12 mV at 10 mA cm –2 and a high turnover frequency (TOF) of 12.2 s –1, with improved HER activity relative to Ru/C and Pt/C under identical testing conditions. Furthermore, the practicality of this effect is demonstrated by the distribution of relaxation time (DRT) analysis in an AEMWE device, providing mechanistic guidance for designing electrocatalysts for alkaline HER.