Synergistic Multi-Metal and Defect Engineering for High-Efficiency Hydrogen Evolution Reaction
Electrochemical water splitting is pivotal for scalable green hydrogen production, yet its practical deployment hinges on 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 merely 0.16% of the cost of Pt. The structure-activity relationship between its microstructure and hydrogen evolution reaction (HER) performance was systematically explored. Lattice defect effects from multiphase intermetallic compounds, combined with multi-metal synergy, optimize H+ adsorption energy and electron transfer kinetics. The 3D nanoporous architecture provides a high electrochemical surface area with abundant active sites, enhancing electrolyte penetration and reducing interfacial mass transfer resistance. Consequently, the ZrVFeCoNi 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 || IrO2/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 catalytic activity, showcasing the potential of 3D nano-structured multiphase intermetallic compounds as high-performance electrocatalysts for green hydrogen systems.