Synthesis Of Ce Based Mixed Oxides Catalysts And Their Catalytic Performances For Methane Combustion And CO Oxidation

At present, the energy crisis and environment deterioration have drawn considerable attention. Methane is a clean fuel, but also a green house gas, so it is significant for the effective utilization and emission control of methane. The catalytic combustion technology is an effective way to the energy acquisition and volatile organic chemicals (VOC) elimination. Compared with the noble based catalysts, Ce based catalysts present higher performance for methane combustion and CO oxidation, with low cost and good thermal stability, which will be an alternative substitute of noble catalysts. China is abundant in rare earths resource, especially for CeO2, so it is necessary for the effective utilization of the rare earths in the fields of environment and energy. In this thesis, series of CeO2 based oxides catalysts were prepared, and their catalytic performances were tested for methane combustion and CO oxidation. The relationships of the catalytic performance-catalyst composition-structure-micromorphology were discussed. The main results are obtained as follows.Ce02-MOx (M=Cu, Mn, Fe, Co and Ni) mixed oxides were prepared by the citric acid complexation-combustion method. It was found that Ce0.9M0.1Oδsolid solution was formed by M cations doping into CeO2 lattice. The catalytic activities of Ce02-MOx for CH4 combustion and CO oxidation were obviously promoted by M cations doped in CeO2. The addition of water vapor in the reaction stream can inhibit the activities of Ce02-MOx for CH4 or CO oxidation reactions. CeO2-NiO presents good water-resistant properties in CH4 combustion. For Ce1-xFexO2 (0