Surface amorphization enables robust catalyst for industrial-level low-potential electrooxidation reactions

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic pollutant oxidation offers energy-efficient valorization but faces catalyst deactivation.
• Overoxidation is a major challenge for existing electrocatalysts, limiting their practical application.

Purpose of the Study:

• To develop a robust electrocatalyst for efficient pollutant oxidation at low potentials.
• To investigate the mechanism behind catalyst stability and activity.

Main Methods:

• Synthesis of amorphous phosphorus-doped CoFe₂O₄ catalyst.
• Electrochemical characterization including current density and potential measurements.
• Long-term stability testing in a hydrazine-assisted electrolyzer.
• Mechanistic studies using electron transfer analysis.

Main Results:

• Achieved industrial-level current densities (1 A cm⁻²) at ultralow potentials for hydrazine, sulfion, and borohydride electrooxidation.
• Demonstrated 400-hour stability at 300 mA cm⁻².
• Revealed electron transfer from Co-P to Co-O ligands, enhancing activity and preventing overoxidation.
• Identified increased positive charges on Co centers as key to lowering activation barriers.

Conclusions:

• The amorphous phosphorus-doped CoFe₂O₄ catalyst offers a new paradigm for designing robust electrocatalysts.
• Decoupling catalytic activity from oxidative deactivation is achievable through ligand-mediated electron transfer.
• This approach enables energy-efficient pollutant valorization and diverse energy applications.