Synergistic multi-metal and defect engineering for high-efficiency hydrogen evolution reaction

Electrochemical water splitting is crucial for the scalable production of green hydrogen; however, the practical implementation requires cost-effective electrocatalysts with high activity and durability. This study introduces a low-cost, three-dimensional (3D) nanoporous ZrVFeCoNi material, fabricated via chemical dealloying, at just 0.16% of the cost of Pt. The structure-activity relationship between its microstructure and hydrogen evolution reaction (HER) performance was systematically explored. The lattice defect effects from multiphase intermetallic compounds, combined with multi-metal synergy, optimize H + adsorption energy and electron transfer kinetics. The 3D nanoporous design provides a high electrochemical surface area with abundant active sites, thereby enhancing electrolyte penetration and reducing interfacial mass transfer resistance. Consequently, the ZrVFe-CoNi electrode exhibits outstanding HER performance, requiring only a 38 mV overpotential to reach 10 mA cm −2 and maintaining stable operation for 1000 h at 500 mA cm −2 . Integrated into a full water electrolyzer (ZrVFeCoNi ∥ IrO 2 /Ni), the system achieves a cell voltage of 1.60 V at a current density of 400 mA cm −2 . Advanced characterization and density functional theory (DFT) calculations reveal that interfacial interactions and charge transfer at heterointerfaces drive the catalytic activity, showcasing the potential of 3D nano-structured multiphase intermetallic compounds as high-performance electrocatalysts for green hydrogen systems.