| 摘 要： | A series of CeO_2-based catalysts with alkaline earth additives for ox-idative coupling of methane (OCM) were investigated using pulse reaction,CO_2-TPD and XRD techniques. The results showed that there were two kindsof lattice oxygen species on the catalyst surfaces responsible for oxidative cou-pling and deep oxidation of CH_4, respectively. The methane deep oxidationprocess was effectively controlled with additional alkaline earth oxides by in-creasing the basicity and modifying the structure of the catalysts. As a result,the adsorbing ability for gaseous oxygen and catalytic performance for OCM re-action were obviously improved. A dynamic equilibrium between producedCO_2 and carbonates on the surface was observed and a spinel Sr_2CeO_4 phase,which may be relevant to the C_2 selectivity enhancing was formed during thecompounding of SrO and CeO_2.
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