Preparation and Physicochemical Characterization of La_(1-x)Ce_xCoO_(3+δ) Perovskite Catalyst and Its Methane Catalytic Combustion

摘要

Perovskite oxide LaCoO3 methane catalytic material was synthesized with citric acid complexation and bubbling method. The effect of doped cerium was studied on the series of La1-xCexCoO3+δ materials by means of BET, XRD and SEM techniques. Their catalytic behaviors were studied with methane catalytic complete combustion as probe reaction. The results show that doped cerium has great effect on crystal phase formation. When doped cerium is less than 0.3 （（molar） ratio）, the crystal phase of oxide has little changed. When doped cerium is up to 0.5, Co3O4 phase is obviously discovered and the perfectibility of LaCoO3 perovskite crystal phase is deteriorated. When x is over 0.7, perovskite crystal phase is weakened or completely disappeared. Considering the crystal phase of oxides, the optimum doped cerium is about 0.3. The perovskite oxides can be formed at a low calcinations temperature of 700 ℃. When x is 0.3, the highest catalytic activity of T10% （390 ℃） and T90% （603 ℃） is obtained on the series of La1-xCexCoO3+δ materials calcined at 800 ℃.