Preparation Of MO/CeO₂ （M=Ni,Cu）Catalysts By Solid State Impregnation And Their Application In CO Oxidation

Part ⅠNiO/CeO2 catalysts with varied NiO loadings were prepared by solid state impregnation and detailed compared with the counterparts from traditional wet impregnation. The catalysts were characterized by XRD, BET, TEM, H2-TPR, Raman and XPS.1. CO oxidation results showed that with the same loading amount of nickel, the catalysts prepared by solid state impregnation displayed higher activities than that prepared by wet impregnation.2. The results of TEM, XPS, H2-TPR demonstrated that solid state impregnation was advantageous to increase the amount of surface dispersed nickel species. This phenomenon revealed that the interaction between nickel and ceria could be strengthened by solid state impregnation, which in turn benefited the reduction of nickel species.3. Raman results showed that by using the solid state impregnation, the oxygen vacancies of catalysts could be enhanced, which promoted oxygen molecules activation and enabled the proceeding of CO oxidation more facile.Part ⅡThe dispersion and physicochemical behaviors of CuO/CeO2 were characterized by XRD, H2-TPR, Raman, XPS, and in situ DRIFTS techniques. Their activities were evaluated by CO+O2 model reaction. The results indicated that:1. The catalysts prepared by solid state impregnation displayed higher activities than that prepared by wet impregnation.2. XPS results demonstrated that solid state impregnation was advantageous to increase the amount of surface dispersed copper species. This phenomenon revealed that the interaction between copper and ceria could be strengthened by solid state impregnation.3. H2-TPR results showed that because of the strengthened interaction between copper and ceria, the catalysts prepared by solid state impregnation chould be reduced more easily. The peak a was corresponding to the reduction of interfacial copper oxide which was highly dispersed and strongly interacted with the support. The peak β was ascribed to the reduction of small clusters with kind of amorphous properties which was XRD-silent.4. Raman and in situ DRIFTS results showed that by using the solid state impregnation, the oxygen vacancies of catalysts could be enhanced and the amount of Cu+ was increased, which enabled the proceeding of CO oxidation more facile.