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本文用XRD、IR、TG、DTA和催化反应色谱法研究了添加Na_2CO_3和第一过渡系列金属氧化物对Sm_2O_3甲烷氧化偶联催化性能的影响。结果表明;随Na_2CO_3含量的逐渐变化,C_2烃的产率和选择性呈现一个复杂的变化过程,0.2wt％CoO的加入使Sm_2O_3丧失了甲烷氧化偶联的活性,而提高了深度氧化活性,CO_2成为唯一的氧化产物;然而,同样量的CoO加入7.8wt％ Na_2CO_3/Sm_2O_3中,却明显提高了生成C_2烃的产率和选择性,其它过渡金属氧化物对7.8wt％ Na_2CO_3/Sm_2O_3的影响与这些氧化物的氧交换性质存在着平行关系,而与它们的表面Me=O键能成反比。本文从Sm_2O_3的n型电导的杂质效应及不同晶相间的相互作用,对催化剂表面氧的吸附量和O~-的吸附强度的影响方面讨论了助剂的作用。
In this paper, XRD, IR, TG, DTA and catalytic reaction chromatography were used to study the effect of adding Na_2CO_3 and the first transition metal oxides on the catalytic activity of Sm_2O_3. The results show that with the gradual change of Na_2CO_3 content, the yield and selectivity of C_2 hydrocarbon show a complicated process. The addition of 0.2wt% CoO causes the loss of methane oxidative coupling of Sm_2O_3 and the increase of deep oxidation activity. However, the same amount of CoO added 7.8wt% Na_2CO_3 / Sm_2O_3, but significantly increased the yield and selectivity of C_2 hydrocarbons. The effect of other transition metal oxides on 7.8wt% Na_2CO_3 / Sm_2O_3 and The oxygen exchange properties of these oxides exist in parallel relationship with their surface Me = O bond can be inversely proportional. In this paper, we discuss the effect of additives on the n-type conductivity of Sm 2 O 3 and the interaction between different crystal phases, the adsorption amount of O 2 on the catalyst surface and the adsorption strength of O 2.