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

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Hydrogen energy is a crucial zero-carbon energy carrier requiring efficient electrocatalysts for hydrogen production.
• Platinum-based catalysts are effective but costly, driving the need for alternative materials.
• High-entropy alloys (HEAs) offer tunable properties but require optimized morphology-composition synergy for enhanced catalysis.

Purpose of the Study:

• To develop high-performance, cost-effective electrocatalysts for the acidic hydrogen evolution reaction (HER).
• To investigate the structure-activity relationship in Pt-doped FeCoNiCuMn HEAs.
• To establish a design principle for multiscale precision engineering of HEAs.

Main Methods:

• Synthesis of Pt$_{x}$FeCoNiCuMn (x = 0-34 at%) high-entropy alloys (HEAs) using a low-temperature one-pot method.
• Synergistic regulation of atomic radius matching and reduction potential gradients for dynamic morphological evolution.
• Comprehensive characterization (e.g., XRD, TEM, XPS) and theoretical analysis to understand HEA properties.
• Electrochemical evaluation of HER performance in 0.5 M H$_{2}$SO$_{4}$.

Main Results:

• Achieved dynamic morphological evolution from nanosheets to nanospheres (2.9 nm) with increasing Pt doping.
• Demonstrated Pt doping concentration-dependent regulation of HEA morphology, lattice structure, and valence states.
• The Pt$_{34}$FeCoNiCuMn HEA-NPs exhibited an ultralow overpotential (η$_{10}$ = 5.1 mV), significantly outperforming commercial Pt/C (η$_{10}$ = 64.7 mV).

Conclusions:

• Established a quantitative structure-activity relationship model linking gradient doping, dynamic reconstruction, and catalytic enhancement.
• Provided theoretical guidance and novel strategies for the precision design of HEAs for HER.
• Developed a highly efficient and potentially cost-effective alternative to Pt-based catalysts for hydrogen production.