Synergistic Dual-Atom\nCatalysts on Ceria for Enhanced\nCO Preferential Oxidation: Insights from High-Throughput First-Principles\nMicrokinetics

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