Dual-Sabatier Optima: How Reaction Mechanism Determines Activity Volcano Map of Dual-Atom Catalysts for Oxygen...

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Dual-atom catalysts (DACs) show promise for the oxygen reduction reaction (ORR).
• Existing models based on associative mechanisms conflict with experimental data.
• A new understanding of ORR mechanisms in DACs is needed.

Purpose of the Study:

• Investigate the dominant ORR mechanism in DACs.
• Develop a predictive model for DAC activity.
• Discover new design principles for efficient ORR catalysts.

Main Methods:

• Thermodynamic and kinetic analysis of 200 DACs.
• Potential-related microkinetic modeling.
• Machine learning (ML) with interpretable structural descriptors.

Main Results:

• The dissociative mechanism is dominant for DACs in ORR.
• A dual-Sabatier optima volcano map was discovered, linked to O2 dissociation and OH protonation steps.
• The findings were validated against experimental data and apply to various DAC compositions.

Conclusions:

• The dissociative mechanism and dual-Sabatier optima are key for ORR in DACs.
• This work provides a new framework for designing DACs and other atomically dispersed catalysts.
• Large-scale data analysis combined with ML can uncover novel catalytic phenomena.