不同结晶度氢型丝光沸石的酸性及其C_8芳烃异构化性能

Acidity and Catalytic Properties of Isomerization of C_8 Aromatic Hydrocarbon on Different Crystalline Mordenites

以间二甲苯和C8芳烃为原料，用脉冲微反技术考察了不同结晶度的丝光沸石C8芳烃异构化性能．采用氨气的程序升温脱附（NH3－TPD）和吡啶吸附的红外光谱法（Py－IR）研究了不同结晶度氢型丝光沸石（HM）的酸中心数、酸强度以及B酸和L酸中心的变化规律，并将HM催化性能、酸性与沸石的微观结构相关联.结果表明，随着结晶度的降低，与骨架铝（T（1），T（2），T（4）相对应的强酸中心被掩蔽，有效地抑制了芳烃脱烷基及歧化等副反应，获得较好的C8芳烃异构化反应活性和选择性，并可制得新型的低结晶度的C8芳烃异构化催化剂。

Using pulse microreaction technique, the isomerizationproperty of C8 aromatic hy drocarbon of different crystalline mordenites were studied with m-dimethyl benzene and C8 aromatic hydrocarbon as reactants. The NH3-TPD and pyridine FT-IR were used to measure the number and the strength of acid sites and the variation regularity of Bronsted and Lewis acid sites with the crytallinity of HM, trying to correlate its catalytic properties and acidity with its microscopic structure. It was found that with the decrease of crystallinity and the strong acid sites related with the framework aluminum T (1 ) 、T (2)and T (4)was covered by the nonframework species, the side reactions of dealkylation and disproportionation of aro matic hydrocarbon were inhibited effectively. A novel catalyst with low degree of crystalline for the isomerization of Cs aromatic hydrocarbon was obtained