Synergistic multi-d orbital hybridization in a PtFeCoNiMnMo high-entropy alloy nanocatalyst for enhanced alkaline hydrogen evolution reaction

Abstract

To address the insufficient activity, low noble metal utilization efficiency, and poor stability of transition metal-based catalysts in alkaline media, a PtFeCoNiMnMo high-entropy alloy (HEA) nanocatalyst with synergistic multi-d orbital hybridization was synthesized via a one-pot solvothermal method using glucose as a dispersant and an auxiliary reducing agent. Comprehensive characterization (XRD, TEM, XPS, and ICP-OES) confirmed its single face-centered cubic structure with lattice distortion (δ = 3.29%), homogeneous elemental distribution, and directional electron transfer-induced strong electronic interactions. Electrochemical tests in 1 M KOH showed exceptional alkaline hydrogen evolution reaction (HER) performance: 21 mV overpotential at 10 mA cm⁻², 47.06 mV dec⁻¹ Tafel slope, 2.455 s⁻¹ TOF, and minimal charge-transfer resistance (5.39 Ω), outperforming control samples and commercial Pt/C. The catalyst exhibited outstanding stability with only 2.1% current decay after 50 h. Mechanistic studies indicated that the multi-d orbital electronic interactions in the alloy can regulate the adsorption capacities of H and OH species, thereby enhancing its alkaline HER catalytic activity.