Boosting the Low-Temperature CO Oxidation Activity of CeO₂ via Photodirected Migration of Au Single Atoms

Single-atom catalysts (SACs) represent a promising solution for maximizing active-site utilization in exhaust gas elimination, yet the restricted functionality of isolated sites in competitive reaction kinetics often limits their performance. In this study, we present a photomediated strategy for the dynamic assembly of multifarious active sites on faceted CeO₂. Combined experimental and theoretical analyses reveal that light-induced migration of Au atoms on 111-CeO₂ transforms neighboring isolated Au atoms into nanoclusters, concurrently activating lattice oxygen near Au single atoms and molecular oxygen around Au nanoclusters. The dual active centers synergistically facilitate CO adsorption and oxygen dissociation of CO, enabling efficient room-temperature CO oxidation through a dual-path mechanism. The photoreconstructed active sites on 111-CeO₂ exhibit remarkable catalytic performance, demonstrating 4-fold and 45-fold enhancement in reaction kinetics compared to conventional 111-CeO₂- and 100-CeO₂-based SACs, respectively, while surpassing state-of-the-art CO oxidation catalysts. This work provides atomic-level insights into metal-support interactions and establishes a novel approach for designing high-performance SACs for environmental catalysis.