A highly active and stable IrOx/SrIrO3 catalyst for the oxygen evolution reaction

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Oxygen electrochemistry is crucial for fuel cells and electrolyzers.
• Slow oxygen evolution reaction (OER) kinetics hinder device performance and commercialization.

Purpose of the Study:

• To develop a highly active and stable catalyst for the oxygen evolution reaction (OER) in acidic electrolytes.
• To investigate the catalytic properties of iridium-based oxides.

Main Methods:

• Synthesized strontium iridium oxide (SrIrO₃) thin films.
• Characterized catalyst formation via strontium leaching during electrochemical testing.
• Performed density functional theory (DFT) calculations to understand active sites.

Main Results:

• Developed an IrO_x/SrIrO₃ catalyst with high specific activity for OER.
• Achieved low overpotential (270-290 mV) at 10 mA/cm² for 30 hours in acidic conditions.
• DFT suggested active IrO₃ or anatase IrO₂ motifs formed on the surface.

Conclusions:

• The IrO_x/SrIrO₃ catalyst exhibits superior performance compared to existing IrO_x and RuO_x systems.
• Strontium leaching effectively creates highly active OER catalytic sites.
• This catalyst shows great promise for advancing electrochemical energy conversion devices.