Preparation of Ce1−xFexO2 solid solution and its catalytic performance for oxidation of CH4 and CO

A series of Ce1−xFexO2 (0 < x ≤ 0.5) catalysts were prepared by the co-precipitation method, and their catalytic performances were investigated for the total oxidation of CO and CH4 as model reactions. X-ray diffraction (XRD) and Raman spectroscopy results show that Ce1−xFexO2−δ solid solutions are formed with x ≤ 0.2. Ce0.9Fe0.1O2 solid solution presents superior catalytic performance for CH4 and CO oxidation, while Ce1−xFexO2 with x > 0.2 shows less active for CO and CH4 oxidation. The results of H2-temperature programmed reduction (H2-TPR), CH4-temperature programmed surface reaction (CH4-TPSR) and CO-TPSR reveal that, the surface oxygen of catalyst is relevant to CO oxidation, which was promoted by the oxygen vacancies formed in Ce–Fe–O solid solution, while the easier lattice oxygen migration property and the favorable reducibility of the catalysts is responsible for the promoted catalytic performance for CH4 oxidation.