Theoretical design principles of Single-Atom Alloys Catalysts for CO Preferential Oxidation from High-Throughput First-Principles Microkinetics

Abstract

Single atom alloys catalysts (SAACs) are regarded as promising candidates for CO preferential oxidation (PROX) catalysis through the inherent potential for site synergistic effects. We report here high-throughput screening of transition-metal (3d, 4d, and 5d) SAACs (MA₁@MB) based on first-principles microkinetics. Dual-site microkinetic analysis for the full PROX network on pristine Cu and Pt surfaces and their SAACs identifies the oxygen-migration-assisted site synergy as the dominant performance driver. Thermodynamic scanning of all reaction pathways suggests a validated simplified network comprising O/OH-migration-assisted COOH path and O₂-predissociated OCOO/OHOH route. Gradient boosting decision tree (GBDT) model on microkinetic solutions for all Cu(111)-based SAAs yields performance landscape characterized by adsorption energies of CO (E_ad(CO#)) and O (E_ad(O#)) at single sites, indicating that optimal SAAs exhibit E_ad(CO#) within the range of -2.4 to -1.7 eV and E_ad(O#) between -2.5 and -1.2 eV. The descriptor set is further expanded across the whole candidate space by incorporating CO, O, and H adsorption energies on host sites via the correlation analysis of energetic parameters at both sites. Based on batch computation of descriptors and GBDT-predicted model, a series of SAACs, including Rh₁@Cu, Rh₁@Ag, and Ni₁@Cu, are recommended for optimal CO adsorption, sufficient oxygen supply, and suppressed H₂ activation. Our theoretical study reveals the promotional effect of SAACs and offers a novel approach for the rational design of SAACs.