Iron-Promoted Dynamic Reconstruction of Perovskite Fluorides Toward Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Controlling catalyst dynamic reconstruction is key for developing efficient oxygen evolution reaction (OER) electrocatalysts.
• Understanding catalytic mechanisms is crucial for designing advanced OER catalysts.

Purpose of the Study:

• To construct highly reconstructable and tunable perovskite fluoride precatalysts for OER.
• To investigate the effect of Fe doping on the structural and electronic properties of KCoₓFe₁₋ₓF₃/NF.
• To elucidate the catalytic mechanism and optimize OER performance.

Main Methods:

• Solvothermal synthesis of KCoₓFe₁₋ₓF₃/NF perovskite fluoride precatalysts.
• Electrochemical characterization (e.g., measuring overpotentials and stability).
• Theoretical analysis (e.g., density functional theory) to understand reaction mechanisms.

Main Results:

• Moderate Fe doping optimized the crystal and electronic structure, promoting reconstruction into active Co/Fe oxyhydroxides.
• The catalysts primarily followed the adsorbate evolution mechanism for OER.
• KCo₀.₈Fe₀.₂F₃/NF demonstrated optimal performance with low overpotentials (230 mV at 10 mA cm⁻² and 267 mV at 100 mA cm⁻²) and >700 h stability.

Conclusions:

• Fe doping enhances OER activity by optimizing intermediate adsorption and lowering the rate-determining step barrier.
• Fluoride precursors offer advantages for constructing high-performance OER catalysts.
• This study provides insights into OER reaction pathways and catalyst design.