Rare-Earth Element-Induced Charge Redistribution in High-Entropy Alloys toward Highly Stable Oxygen Evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transitional metal (TM)-based high-entropy alloys (HEAs) show promise for oxygen evolution reaction (OER) catalysis.
• However, HEAs suffer from instability due to oxidation and structural degradation during operation.

Purpose of the Study:

• To enhance the stability of HEAs for OER by introducing cerium (Ce) for charge redistribution.
• To investigate the mechanism of Ce-mediated electronic modulation in FeCoNiMnCe HEA for improved OER performance.

Main Methods:

• Synthesis of FeCoNiMnCe high-entropy alloy.
• Electrochemical characterization of OER activity and durability.
• Analysis of electronic structure and charge transfer dynamics.

Main Results:

• The FeCoNiMnCe HEA exhibited enhanced OER durability, with negligible decay over 1000 hours at 10 mA cm⁻².
• The cerium-mediated strategy increased the dissolving activation energy of Fe/Mn and optimized Co/Ni electronic orbitals.
• Stable operation of zinc-air batteries for 4600 hours at 2 mA cm⁻² was achieved.

Conclusions:

• Cerium-mediated charge redistribution is an effective strategy for designing stable HEA electrocatalysts.
• Targeted electronic modulation can inhibit active site deactivation and improve catalytic performance.
• This approach offers a pathway for developing robust electrocatalysts for energy applications.