Effects of CeO_2 Addition to W-Mn/SiO_2 Catalysts for Oxidative Conversionof Methane at Elevated Pressure

摘要

In the last two decades, most of the attention on the direct conversion of methane has been devoted to the oxidative coupling reaction (OCM), which involves the catalytic conversion of methane with oxygen to C_(2+) hydrocarbons and water. One of the most effective catalysts for the OCM is Mn/Na_2WO_4/SiO_2, the groups leaded by Li, Lunsford and Lambert have studied for the OCM over the catalyst on the elementary reaction, role of active composition. We also found that a small amount of C_3-C_4 hydrocarbons were produced under different conditions, particularly at elevated pressure. Through analysis of several reviews and comprehensive process, implicit has been the assumption that the high conversions of methane and selectivity of higher hydrocarbons would be achieved under elevated pressure. Unfortunately, there is little report on higher pressure for catalytic oxidation of methane to higher hydrocarbons. The present paper reports that effects of pressure on crystalline phase structure and catalytic activity for oxidative conversion of methane to C_2-C_4 hydrocarbons.