Mesoporous Ce1 − x Fe x O2 mixed oxide catalysts of different molar ratios ( x = 0.1–0.5) were prepared by the citric acid sol-gel method and the microwave technique. The activities of Ce1 − x Fe x O2 mixed oxides on methane combustion were investigated, and the structure and reductive properties were characterized by XRD, BET, DRS, and TPR. The data showed that Ce1 − x Fe x O2 mixed oxides prepared were mesoporous material. When x ≤ 0.2, the transition metal Fe incorporated into the lattice of CeO2 to form cubic Ce1 − x Fe x O2 solid solutions, and mixed phases of cubic Ce1 − x Fe x O2 solid solutions and α-Fe2O3 existed when x > 0.2. Ce1 − x Fe x O2 solid solutions show higher activity for methane combustion than pure CeO2, especially for Ce0.9Fe0.1O2. [ABSTRACT FROM AUTHOR]