Abstract:A series of SrCO3/La2O2CO3 catalysts prepared by thermal decomposition and co-precipitation method were tested in low-temperature OCM (oxidative coupling of methane). The choice of precipitators played great role on the catalytic performance, and the catalysts obtained by the multiple precipitators NaOH/Na2CO3 showed better activity and stability than the catalysts obtained by single precipitator. Both tetragonal (I-) and hexagonal (II)-La2O2CO3 was detected in the catalysts, and their coexistence provided two types of active sites for OCM to produce C2 and deep oxidation of methane to produce COx, respectively. The later reaction was high exothermic, which provided the hot spot for the ignition of the OCM reaction, and great energy to maintain the reaction. The catalyst with 25 mol.% of SrCO3 could hold the reaction for at least 24 h at Tex=100 oC (external furnace temperature) with CH4 conversion of 25.6% and C2 selectivity of 43.4%.