Ultrastable supported oxygen evolution electrocatalyst formed by ripening-induced embedding

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane water electrolyzer (PEMWE) technology requires efficient, stable, and cost-effective oxygen evolution catalysts for terawatt-scale deployment.
• Iridium (Ir) catalysts, while active, suffer from poor stability due to dissolution, redeposition, detachment, and agglomeration.

Purpose of the Study:

• To develop a novel strategy for stabilizing iridium catalysts for oxygen evolution reactions in PEMWEs.
• To improve the long-term durability and efficiency of PEMWEs through catalyst support engineering.

Main Methods:

• A ripening-induced embedding strategy was employed to anchor iridium catalyst nanoparticles within a cerium oxide support.
• Cryogenic electron tomography and all-atom kinetic Monte Carlo simulations were used to analyze the synthesis mechanism.
• Accelerated aging tests (6000 hours) were conducted to evaluate catalyst stability and performance.

Main Results:

• The embedding strategy successfully stabilized iridium species, preventing degradation.
• The synthesized catalyst achieved a low Ir loading (0.3 mg/cm²) with high performance (1.72 V at 3 A/cm²).
• Exceptional long-term stability was demonstrated with a voltage degradation rate of 1.33 µV/h.

Conclusions:

• Synchronizing support growth and Ir nucleation via sonication is crucial for effective catalyst embedding.
• The developed embedded Ir catalyst offers a promising solution for stable and efficient oxygen evolution in future PEMWE systems.
• This approach paves the way for cost-effective and durable catalysts essential for large-scale green hydrogen production.