PtRuCoNiCu High-Entropy Alloy Nanodendrites for Efficient Electrocatalytic Reactions

The shift to sustainable energy requires efficient hydrogen production through water electrolysis. However, alkaline hydrogen evolution reaction (alkaline HER) technologies suffer from slow kinetics, high overpotential (>200 mV), and dependence on expensive Pt/Ru catalysts. High-entropy alloys (HEAs) offer promising tunability but suffer from oxidative deactivation, disordered active sites, and limited surface area. Herein, we first synthesize PtRuCoNiCu HEA nanodendrites (HEA-NDs) via a one-pot hydrothermal method, featuring a defect-rich 3D branching structure. The shortened Pt–Pt bond (2.61 Å) induces tensile strain, optimizing the hydrogen adsorption energy (ΔG*H = – 0.06 eV). The HEA-NDs achieve an ultralow overpotential of 10 mV at 10 mA cm–2 (82% lower than Pt/C), a Tafel slope of 23.4 mV dec–1, and greater than 95% stability over 100 h. Notably, they also exhibit exceptional mass activity in the methanol oxidation reaction (MOR) (4830 mA mg–1) and CO antipoisoning capability, demonstrating multifunctional catalytic superiority. The excellent catalytic performance of HEA-NDs is further elucidated by density functional theory-based mechanistic studies of HER and MOR pathways. The synergy between lattice strain and high-entropy effects in these dendritic nanostructures establishes a new paradigm for designing next-generation electrocatalysts for water electrolysis.