N₂ treatment triggered self-reorganization into fully exposed platinum cluster catalysts for efficient low-temperature CO oxidation

The development of efficient low-load platinum catalysts for CO oxidation is critical for large-scale industrial applications and environmental protection. In this study, a strategy of N₂ treatment triggered the self-reforming into fully exposed Pt cluster catalysts was proposed. By adjusting the coordination environment of Pt species on the defect support through N₂ treatment, the CO catalytic activity was significantly enhanced, achieving complete CO oxidation at 130 ℃ with a Pt loading of only 0.1 wt.%. The turnover frequency of N₂-treated Pt_FEC/Ti-D at 160 ℃ was 18.3 times that of untreated Pt_SA/Ti-D. Comprehensive characterization results indicated that the N₂ treatment of the Pt single-atom defect catalyst facilitated the reconfiguration and evolution of the defect structure, leading to the aggregation of Pt single atoms into fully exposed Pt clusters. Notably, these fully exposed Pt clusters exhibited a reduced coordination of Pt-O in the first coordination shell compared to single atoms, which resulted in the formation of Pt-Pt metal coordination. This unique coordination structure enhanced the adsorption and activation of CO and O₂ on the catalyst, thereby resulting in exceptional low-temperature CO oxidation activity. This work demonstrates a promising strategy for the design, synthesis, and industrial application of efficient low-platinum load catalysts.