Potential-dependent O-O Coupling Mechanism for Oxygen Evolution Reaction on Ruthenium Dioxide

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Developing efficient and stable oxygen evolution reaction (OER) catalysts is crucial for proton exchange membrane water electrolysis (PEM-WE).
• Ruthenium dioxide (RuO2) is a promising alternative to iridium dioxide (IrO2) due to its higher activity and lower cost, but its long-term stability needs improvement.
• Understanding the fundamental mechanisms of OER on RuO2 is essential for catalyst design.

Purpose of the Study:

• To elucidate the potential-dependent OER mechanisms on the RuO2(110) facet.
• To investigate the thermodynamic and kinetic factors influencing RuO2 catalyst performance.
• To provide insights for designing more stable and active OER electrocatalysts.

Main Methods:

• Grand Canonical density functional theory (GC-DFT) calculations were employed to study the reaction pathways.
• Microkinetic modeling (MKM) was used to analyze the reaction kinetics.
• The OER mechanisms on the pristine RuO2(110) surface were investigated.

Main Results:

• The study confirmed the dominant role of the Adsorption-Electrode-Metal (AEM) mechanism.
• The Lattice Oxygen Mechanism (LOM) and Oxygen Precipitation Mechanism (OPM) were found to be less likely on the pristine RuO2(110) surface.
• Detailed mechanistic understanding of OER on RuO2 was achieved from both thermodynamic and kinetic viewpoints.

Conclusions:

• This research deepens the mechanistic understanding of OER on RuO2.
• The findings provide a foundation for the rational design of high-performance OER electrocatalysts.
• The study highlights the importance of considering both thermodynamics and kinetics for catalyst development.