甲烷分子在碱性催化剂上的吸附与酸碱活化机理

Methane Adsorption and Activation Mechanism by Acid/Base Pairs over Base Catalysts

以碳酸锶为甲烷吸附活化的模型催化剂，用切换瞬变应答、ＣＨ４（ＣＯ２）ＴＰＤ等技术，对甲烷的吸附、碱性对催化剂性能的影响进行了研究．结果表明，甲烷在碳酸锶上的活化显示出明显的酸碱活化机理特征．瞬变应答及ＴＰＤ结果均证明，甲烷在碳酸锶表面有较强的吸附，其脱附温度约３１０℃．关联结果表明，甲烷转化率及Ｃ２烃收率与催化剂表面ＳｒＯ碱性中心浓度间有非常一致的顺变关系，因此催化剂表面的酸碱中心可能是甲烷的选择活化中心．

The model catalyst of strontium carbonate was prepared for the study of methane activation mechanism using Trasient Switch Response (TSR) and CH 4(CO 2) TPD techniques. The interaction of methane with the surface of SrCO 3 was investigated and the adsorption of CH 4 as well as the influence of basicity on the reactivity was discussed in some depth. It is revealed from the catalyst test that the activation of methane showed the characteristics of acid/base pair mechanism clearly over SrCO 3. The result of TSR brought to light the strong adsorption of CH 4 and a desorption peak of methane appeared at ca.310℃ in the CH 4 TPD profile. A strong argument for the acid/base pairs being directly responsible for the selective activation of CH 4 is that CH 4 conversion, C 2 yield and the concentration of SrO all changed in the same manner with temperature for SrCO 3.