Synergistic Dual-Atom Catalysts on Ceria for Enhanced CO Preferential Oxidation: Insights from High-Throughput First-Principles Microkinetics

Highly dispersed transition metal atoms supported by reducible ceria have garnered considerable attention as CO preferential oxidation (PROX) catalysts. Dual-atom catalysts (DACs), which effectively balance activity and selectivity through synergistic effects, are promising candidates for PROX catalysis. We report here the high-throughput screening of CeO 2 (110)-supported DACs (M A -M B /CeO 2, M A(B) = 3d, 4d, 5d transition metal) based on first-principles microkinetics. Reduced electronegativity and d-orbital population of metal atoms favor the stability of loaded DACs via binding energy and aggregation energy analyses. A state-to-state microkinetic analysis of the full PROX reaction network identifies that the O 2 -predissociated Mars–van Krevelen (MvK) pathway, characterized by direct oxidation, carbonate formation, and interfacial oxygen migration, is the predominant mechanism on M A -M B /CeO 2 under low temperatures. The key energetic routes of homogeneous DACs reveal that the oxygen removal energy of dissociated O 2 and adsorption energies of CO and H on transition metal sites serve as effective descriptors of PROX performance. Following these insights, high-throughput computations of PROX descriptors are carried out on a combination of 435 heterogeneous DACs to screen catalysts with balanced activity and selectivity. Au-based DACs, notably Fe–Au, stand out at room temperature for their facile activation of dissociated oxygen and moderated hydrogen affinity. Our study harnesses the unique properties of dual-atom configurations and paves way for the rational design of efficient PROX catalysts.