Two-dimensional iridium-cobalt oxide for high-efficiency acidic oxygen evolution reaction electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Inorganic Chemistry

Background:

• Efficient electrocatalysts are vital for sustainable energy technologies like water electrolysis.
• Developing robust electrocatalysts for the oxygen evolution reaction (OER) in acidic media remains a significant challenge.

Purpose of the Study:

• To synthesize a novel two-dimensional iridium-cobalt oxide material.
• To evaluate its performance as an electrocatalyst for the oxygen evolution reaction (OER) in acidic media.
• To assess its stability during proton exchange membrane water electrolysis.

Main Methods:

• Molten-alkali mechanochemical synthesis of a two-dimensional iridium-cobalt oxide.
• Electrochemical characterization in 0.5 M sulfuric acid (H2SO4) to determine overpotential for OER.
• Long-term stability testing during proton exchange membrane water electrolysis at a constant voltage.

Main Results:

• The synthesized iridium-cobalt oxide exhibited a low overpotential of 256 mV at a current density of 10 mA cm⁻² for OER.
• The material demonstrated exceptional stability, operating continuously for 600 hours at 1.7 V during water electrolysis.
• The two-dimensional structure facilitated efficient electrocatalytic activity.

Conclusions:

• The molten-alkali mechanochemical method is effective for synthesizing advanced 2D oxide electrocatalysts.
• The novel iridium-cobalt oxide shows great promise as a highly stable and efficient electrocatalyst for acidic water electrolysis.
• This material could significantly advance proton exchange membrane water electrolyzer technology.