Controlled Structural Activation of Iridium Single Atom Catalyst for High-Performance Proton Exchange Membrane Water...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Iridium single atom catalysts are key for oxygen evolution reaction (OER) in proton exchange membrane water electrolysis (PEMWE).
• Limited stability of these catalysts hinders practical application in PEMWE.
• Reducing reliance on costly iridium is crucial for efficient OER catalysis.

Purpose of the Study:

• To enhance the activity and stability of iridium-doped CoMn2O4 for acidic OER.
• To enable long-term operation of proton exchange membrane water electrolysis (PEMWE).
• To investigate the structural evolution and catalytic mechanism of the activated catalyst.

Main Methods:

• Synthesis and activation of Ir-doped CoMn2O4.
• In-depth material characterization (e.g., TEM, XPS).
• Electrochemical analysis (OER performance, stability testing) and theoretical calculations.

Main Results:

• Activation induced restructuring of single Ir atoms into IrO2 nanoclusters.
• Achieved mass activity of 3562 A gIr-1 at 1.53 V (vs RHE).
• Demonstrated stable PEMWE operation for >1000 h at 250 mA cm-2 and >400 h at 1000 mA cm-2.

Conclusions:

• The activated Ir-doped CoMn2O4 exhibits excellent activity and durability for acidic OER.
• The optimized Ir nanocluster configuration is responsible for the enhanced performance.
• The catalyst shows practical applicability for long-term, high-performance PEMWE.