【摘要】 报导了表面相Li在甲烷氧化偶联反应中的作用。应用XRD,SEM,ESR及IR-PAS等技术对Li-Mn-Mg-O催化剂体系表面相的组成、结构及活性进行了测试,发现C₂产物的生成量同表面相Li的含量有较好的对应关系。同时发现含Li催化剂的失活同表面相Li的流失有密切的关系。表面Li的流失可借助体相Li在适当温度下扩散得到补充,但这种补充也是很有限的。更多还原

【Abstract】 The function of surface lithium in the catalytic oxidative coupling of methane was studied by using XRD, SEM, ESR and IR-PAS techniques, the surface composition, structure and the activity of Li-Mn-MgO catalysts for the given reaction were determined. The experimental results revealed that there existed a parallel correlation between the C2 hydrocarbon yield and the lithium content of catalyst. The deactivation of the Li-containing catalysts was related to the loss of surface Li and the lost surface Li could be compensated by the bulk Li diffusing to the surface at proper temperature, however, the compensation was limited to a large extent.更多还原