Electronic Structure Modulation Coupled with Vacancy Defect Engineering in FeCoNiCrV High-Entropy Alloy...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High-entropy alloys (HEAs) offer unique properties for catalysis.
• Strategic engineering of composition and defects in HEAs is crucial but underexplored.
• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is vital for energy technologies.

Purpose of the Study:

• To synthesize and characterize a novel FeCoNiCrV high-entropy alloy (HEA) electrocatalyst.
• To investigate the role of defect engineering in enhancing OER performance.
• To elucidate the structure-activity relationship in HEA catalysts through dynamic self-reconfiguration.

Main Methods:

• Filtered cathode vacuum arc deposition for HEA synthesis on carbon cloth.
• Electrochemical testing in alkaline media to evaluate OER performance (overpotential, stability).
• In situ/ex situ characterization techniques to study catalyst self-reconstruction and defect formation.

Main Results:

• The optimized FeCoNiCrV HEA catalyst achieved an ultralow OER overpotential (254 mV at 10 mA cm⁻²).
• Exceptional operational stability was demonstrated, sustaining 710 h at 20 mA cm⁻².
• Catalyst self-reconstruction led to oxygen vacancy generation, enhancing charge transfer and optimizing adsorption energetics.

Conclusions:

• Defect engineering via electrochemical self-reconfiguration is a universal design principle for HEA electrocatalysts.
• The synergistic effect of multimetallic coordination and defect-rich architecture optimizes catalytic activity and stability.
• This study provides atomic-level insights into the structure-activity interplay in complex multicomponent catalytic systems.