Abstract: Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ and _0.5Sr_0.5Co_0.8Ti_0.2O_3-δ oxides were synthesized by a combined EDTA-citrate complexing method. The catalytic behavior of these two oxides with the perovskite structure was studied during the reaction of methane oxidation. The pre-treatment with methane has different effect on the catalytic activities of both the oxides. The methane pre-treatment has not resulted in the change of the catalytic activity of BSCFOowing to its excellent reversibility of the perovskite structure resulting from the excellent synergistic interaction between Co and Fe in the oxide. However, the substitution with Ti on Fe-site in the lattice makes the methane pre-treatment have an obvious influence on the activity of the formed BSCTO oxide.

Key words: Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ, Ba_0.5Sr_0.5Co_0.8Ti_0.2O_3-δ, Partial oxidation of methane, CH₄ pre-treatment