Research progress on single-atom catalysts for carbon monoxide oxidation

Low-temperature catalytic oxidation of carbon monoxide is of great significance for atmospheric environmental protection and the control of industrial emissions. Single-atom catalysts offer distinct advantages due to their excellent atomic utilisation, uniform active sites and unique electronic structure. This opens up new opportunities for CO oxidation reactions and serves as a bridge between homogeneous and heterogeneous catalysis. This paper provides a systematic review of research progress on single-atom catalysts in the field of CO oxidation. The article commences with a comprehensive overview of diverse synthesis strategies and anchoring mechanisms of single-atom catalysts, followed by an in-depth discussion of the application of pivotal characterisation techniques in atomic-scale analysis of the active site structure. Subsequently, the focus is directed towards the catalytic performance, reaction mechanism, and structure–activity relationship of various noble metal single-atom catalysts in CO oxidation. The study demonstrates that by precisely regulating the coordination environment of metal single atoms and their interactions with the carrier, catalytic activity and stability can be significantly enhanced. In conclusion, the article synthesises the optimisation strategies employed, including the introduction of a second metal and carrier defect engineering, to surmount the challenges associated with the stability and metal loading of single-atom catalysts. It further provides a prospective perspective on future research directions. This review provides a theoretical basis and technical reference for the rational design of high-performance single-atom catalysts for CO oxidation.