Stress-ligand synergistic effect in copper‑nickel binary alloys enables enhanced hydrogen evolution activities

We exploited stress-ligand synergistic effect on copper–nickel binary alloys for enhanced hydrogen evolution reaction in alkaline environment. Alloys with varied compositions were fabricated via deformation-driven metallurgy under ambient and cryogenic conditions to modulate residual stress. Microstructural analysis revealed significant grain refinement and compressive stress generation, especially in cryogenic-processed Cu3Ni7 (atomic fraction) samples. Electrochemical characterization demonstrated that Cu3Ni7 exhibited an overpotential of 103 mV at 10 mA cm⁻², approaching Pt foil performance. Density functional theory calculations correlated residual stress with Gibbs free energy of hydrogen adsorption and d-band center shifts, confirming that stress-induced lattice deformation and ligand effect between nickel and copper jointly enhance water dissociation and hydrogen adsorption. Based on the experimental and calculation results, we further established a mechanistic link between d-band tuning, residual stress, and catalytic performance for the first time, providing a pathway for cost-effective transition-metal hydrogen evolution electrocatalysts.