Enhanced Catalytic Performance of Three-Dimensional Ordered Mesoporous Transition Metal (Co, Cu, Fe)-Doped CeO2 Catalysts for CO Catalytic Oxidation

Transition metal (Co, Cu, Fe)-doped CeO2 catalysts with three-dimensional mesoporous channels had been synthesized through a nanocasting route using three-dimensional mesoporous silica KIT-6 as the template. All four catalysts exhibited high surface area (>120 m2 g−1) and ordered mesopore. The research results showed that Co3O4, CuO, Fe2O3 crystallites in catalysts were encapsulated by nanosized CeO2, respectively, and a small fraction of Co, Cu, Fe ions were exposing on the surface and strongly interacting with CeO2. These ions (Co, Cu, Fe) maximized interaction with Ce ion in three-dimensional mesoporous structure, resulting in unique redox properties. The research results showed that the introduction of promoter (Co, Cu and Fe species) could effectively enhance the chemisorbed oxygen and oxygen vacancy concentration on the surface of metal-doped CeO2 catalysts. Compared with Co and Fe species, the Cu species had an obvious enhancement. The characteristic was relatively conducive to the catalytic oxidation of CO. The catalysts were evaluated for the catalytic oxidation CO reaction. The Cu-doped CeO2 catalyst exhibited the highest catalytic activity, and complete conversion temperature (T100) was about 50 °C for CO oxidation.