Constructing high-density CuO-TiO2 heterointerfaces for enhanced low-temperature CO oxidation and SO2 resistance

CuO-based catalysts have garnered significant attention for CO oxidation reaction, while their susceptibility to sulfur poisoning limits their practical application in industrial flue gas treatment. In this study, three CuTi oxide catalysts with distinct CuO-TiO 2 heterointerfaces were prepared by sol-gel, impregnation, and mechanical mixing methods to investigate the influence of interfacial structure on CO oxidation activity and SO 2 tolerance. Catalytic performance and characterization show that a high-density CuO-TiO 2 heterointerface can induce the formation of strong Cu Ti interactions and improve the dispersion of copper species. These effects facilitate CO adsorption and increase oxygen vacancy concentration, thereby enhancing the low-temperature CO oxidation activity. Although the high-density heterointerface enhances SO 2 adsorption capacity, the accompanying strong Cu Ti interaction reduces the stability of copper sulfate (Cu-O-S) species. This promotes the decomposition of copper sulfate and helps preserve active sites, thus improving SO 2 tolerance. This work offers new insights into the rational design of sulfur-tolerant CuO-based catalysts for CO oxidation.