Effect of Different Pore Structures on the Surface Textures of the Cu-Doped CeO2 Catalysts and Applied for CO Catalytic Oxidation

By using mesoporous silica KIT-6 with different hydrothermal temperature as a template, Cu-doped CeO2 catalysts with different pore diameters were successfully prepared. When KIT-6-50 (hydrothermal synthesis of mesoporous silica KIT-6 temperature was 50 °C) and KIT-6-100 (hydrothermal synthesis of mesoporous silica KIT-6 temperature was 100 °C) were employed as the hard template, the uncoupled sub-framework Cu-doped CeO2 catalyst formed. When KIT-6-130 (hydrothermal synthesis of mesoporous silica KIT-6 temperature was 130 °C) was employed as the hard template, the coupled sub-framework Cu-doped CeO2 catalyst formed. Compared with the coupled sub-framework Cu-doped CeO2 catalyst, the uncoupled sub-framework Cu-doped CeO2 catalyst has the higher surface areas and more open system. The Cu-doped CeO2 catalyst with KIT-6-50 as a template exhibited the highest catalytic activity, and complete conversion temperature (T100) was about 53 °C for CO oxidation. Besides, it was investigated that there were more chemisorbed oxygen and oxygen vacancy on the surface of Cu-doped CeO2 with KIT-6-50 as a template catalyst by XPS analysis. It could be concluded that the higher surface area and more open system was relatively conducive to the catalytic oxidation of CO. At the same time, the chemisorbed oxygen and oxygen vacancy also played an important role in CO catalytic oxidation.