Enhanced Acidic Oxygen Evolution Reaction Performance by Anchoring Iridium Oxide Nanoparticles on Co₃O₄.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Sluggish oxygen evolution reaction (OER) kinetics hinder proton exchange membrane water electrolyzer (PEMWE) industrial application.
• Developing efficient and stable OER electrocatalysts is crucial for advancing water electrolysis technology.

Purpose of the Study:

• To synthesize and characterize a high-performance IrO2@Co3O4 electrocatalyst for OER.
• To investigate the catalytic activity, stability, and underlying mechanisms of the novel catalyst in acidic media.

Main Methods:

• A two-step combustion method was employed to anchor iridium oxide nanoparticles (IrO2) onto a cobalt oxide (Co3O4) substrate.
• Electrochemical measurements, including overpotential determination at 10 mA cm-2 and long-term stability tests (80 h), were conducted.
• Energy spectrum characterizations and theoretical calculations were utilized to elucidate the catalytic mechanism.

Main Results:

• The IrO2@Co3O4 catalyst exhibited enhanced OER activity with an overpotential of 301 mV at 10 mA cm-2.
• Exceptional stability was demonstrated, with minimal overpotential increase over 80 hours of operation.
• Strong IrO2-Co3O4 interaction was identified as key, promoting OER-active Ir3+ species and stabilizing active sites.

Conclusions:

• The synthesized IrO2@Co3O4 catalyst offers a promising solution for efficient and stable OER in acidic environments.
• The synergistic interaction between IrO2 and Co3O4 significantly enhances catalytic performance and durability.
• This work provides valuable insights for designing next-generation OER electrocatalysts for industrial water electrolysis.