Synergistic Dual-Atom Catalysts on Ceria for Enhanced CO Preferential Oxidation: Insights from High-Throughput First-Principles Microkinetics
Zhang Liu, Yanwei Wen, Zhaojie Wang, Limin Guo, Rong Chen, Aimin Zhang, Bin Shan
Abstract
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.