Dynamic Reconstruction of Pt Gradient Doping in High‐Entropy Alloys for Efficient Hydrogen Production

Abstract Hydrogen energy, as a zero‐carbon energy carrier, urgently requires high‐performance acidic hydrogen evolution reaction (HER) electrocatalysts. To address the challenges posed by costly Pt‐based catalysts and the morphology‐composition synergy in high‐entropy alloys (HEAs), Pt x FeCoNiCuMn ( x = 0‐34 at%) HEAs are developed using a multicomponent synergy design principle. Through the synergistic regulation of atomic radius matching and reduction potential gradients, dynamic morphological evolution from nanosheets (amorphous) → nanosheet‐nanoparticle heterostructures → single‐phase nanospheres (2.9 nm) is achieved via a low‐temperature one‐pot synthesis. Comprehensive characterization and theoretical analysis reveal a Pt‐doping concentration‐dependent regulation of HEAs morphology, lattice structure, and valence states. Experimental results demonstrate that the Pt 34 FeCoNiCuMn HEA‐NPs achieves exceptional HER performance in 0.5 m H 2 SO 4 , delivering an ultralow overpotential of η 10 = 5.1 mV, significantly outperforming commercial Pt/C (η 10 = 64.7 mV). This work establishes a quantitative “gradient doping‐dynamic reconstruction‐catalytic enhancement” structure‐activity relationship model, providing theoretical guidance and novel strategies for the multiscale precision design of HEAs.