Engineering High-Density Grain Boundaries in Ru_0.8Ir_0.2O_x Solid-Solution Nanosheets for Efficient and Durable OER...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• The oxygen evolution reaction (OER) is critical for green hydrogen production via water electrolysis but faces challenges like sluggish kinetics and poor durability.
• Proton exchange membrane water electrolyzers (PEMWE) require highly efficient and stable OER catalysts to overcome these limitations.

Purpose of the Study:

• To develop a novel catalyst design for enhanced OER performance in PEMWE.
• To investigate the role of grain boundaries and metal synergy in catalyst activity and stability.

Main Methods:

• Fabrication of solid-solution Ru0.8Ir0.2Ox ultrathin nanosheets with engineered grain boundaries.
• Electrochemical characterization including overpotential measurements and durability testing.
• In situ electrochemical techniques and theoretical calculations to elucidate reaction mechanisms.

Main Results:

• The engineered Ru0.8Ir0.2Ox nanosheets achieved an overpotential of 189 mV at 10 mA cm-2 in acidic electrolyte.
• Demonstrated industrial-scale performance in PEMWE, reaching 4.0 A cm-2 at 2 V and >1000 h stability at 500 mA cm-2.
• Significantly reduced hydrogen production costs to $0.88 kg-1.

Conclusions:

• Strategic grain boundary engineering and synergistic Ir-Ru interactions in Ru0.8Ir0.2Ox nanosheets effectively enhance OER kinetics and durability.
• This catalyst design offers a promising pathway for efficient and cost-effective green hydrogen production.
• The findings advance the development of next-generation catalysts for sustainable energy technologies.