Descriptor-Driven Designed FeCoNiMoV High-Entropy Alloys for Exceptional Oxygen Evolution Activity

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Oxygen evolution reaction (OER) typically uses scarce noble metal electrocatalysts with limited activity and stability.
• High-entropy alloys (HEAs) present compositional flexibility for improved OER performance, but design principles and synthesis methods are underdeveloped.

Purpose of the Study:

• To develop FeCoNi-based HEA catalysts for efficient OER using a descriptor-guided screening and MOF pyrolysis approach.
• To elucidate the catalytic mechanism of HEAs in OER through a combined theoretical and experimental investigation.

Main Methods:

• Descriptor-guided screening for HEA catalyst design.
• Core-shell metal-organic framework (MOF) pyrolysis for scalable HEA synthesis.
• Electrochemical testing in alkaline media to evaluate OER performance (overpotential, Tafel slope).
• Theoretical calculations and surface analysis to understand the catalytic mechanism.

Main Results:

• FeCoNiMoV HEA catalysts demonstrated exceptional OER activity with a low overpotential (212 mV at 10 mA/cm²) and an ultralow Tafel slope (41.33 mV/dec).
• The catalysts exhibited excellent long-term stability in alkaline conditions.
• Surface reconstruction via preferential leaching of V/Mo was identified as key to forming active high-valence Ni/Co species and enabling dual-pathway activation.

Conclusions:

• The study presents a successful strategy for designing and synthesizing high-performance HEA electrocatalysts for OER.
• A universal design framework for HEA catalysts was established, paving the way for accelerated development in the field.
• The findings provide crucial insights into the OER catalytic mechanisms of HEAs.