Surface structure and catalytic properties of MoO_3/CeO_2 and CuO/MoO_3/CeO_2

摘要

XRD, LRS, TPR and in situ NH_3 adsorption FT-IR were used to investigate the dispersion state of the copper oxide and molybdena species of MoO_3/CeO_2 and CuO/MoO_3/CeO_2 catalysts as well as their surface acidity. The results showed that the molybdena monolayer modification promoted the dispersion of CuO due to the formation of new tetrahedral vacancies. Meanwhile, CuO changed the structure of molybdenum species and then influenced the surface acidity of the samples. A detail discussion about the possible model of the surface structure of the catalyst was presented. In addition, combining with the in situ NH_3 adsorption FT-IR, the relationships between the activities for ''NO+NH_3+O_2'' reaction and surface acid properties (Br?nsted and Lewis acid sites) of the catalysts were discussed.