Mapping Distinct Oxygen-Binding Regimes in Single-Atom Alloys

Area of Science:

• Heterogeneous catalysis
• Materials science
• Computational chemistry

Background:

• Single-atom alloys (SAAs) offer vast potential for designing novel heterogeneous catalysts.
• Adsorbate binding on SAAs lacks a universal predictive principle, hindering rational design.
• Understanding oxygen binding is crucial for many catalytic applications.

Purpose of the Study:

• To identify and characterize distinct adsorption regimes for oxygen on single-atom alloys.
• To develop a framework for predicting oxygen binding across diverse alloy compositions.
• To enable more accurate high-throughput screening of single-atom alloys for catalysis.

Main Methods:

• Performed over 1,000 density functional theory (DFT) calculations.
• Combined interpretable machine learning with descriptor analysis.
• Identified three distinct governing mechanisms for oxygen adsorption.

Main Results:

• Oxygen binding is governed by three distinct physical regimes: d-band center theory (early transition metals), ten-electron counting rule (late transition metals), and coordination effects.
• Developed a regime-based framework explaining adsorption trends across chemically diverse alloys.
• Demonstrated the limitations of conventional global models for SAA adsorption.

Conclusions:

• Adsorption-regime mapping provides a more reliable approach for predicting oxygen binding on single-atom alloys.
• This framework moves beyond single-descriptor models, supporting interpretable catalyst discovery.
• The findings facilitate the rational design and high-throughput screening of advanced single-atom alloy catalysts.