Synergistic Cascade Hydrogen Evolution Boosting via Integrating Surface Oxophilicity Modification with Carbon Layer Confinement

Abstract The lack of highly efficient catalysts severely hinders large‐scale application of electrochemical hydrogen evolution reaction (HER) for hydrogen production from water. Herein, synergistic cascade hydrogen evolution boosting by combining the strategies of carbon layer confinement and surface oxophilicity modification is realized. The carbon layers confined ultrafine RuCr nanoparticles (RuCr@C) exhibit outstanding HER activity (j₁₀ = 19 mV, turnover frequency = 4.25 H₂ s^‐1), surpassing the benchmark Pt/C and most of the reported HER catalysts. Combined experimental verifications and theoretical simulations reveal that surface adsorption modification and electronic structure regulation synergistically boosts the HER kinetics over the RuCr@C catalyst. The Volmer step is accelerated by stabilizing the final state of water dissociation (*H and *OH) through Cr doping, and the Heyrovsky step is promoted via carbon layers confinement. As such, this work highlights a synergistic cascade strategy to boost HER kinetics which is of fundamental importance to accelerate future advances in electrocatalysis.