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讨论了HZSM-5的离子交换度、反应条件及反应物结构对催化性能的影响。实验发现,在离子交换度分别为60%(用乙酸和乙醇酯化时)和70%(用乙酸和正丁醇酯化时)时,催化活性出现一个迅速增加的转折点。这种现象和沸石表面酸中心的强度及反应物分子的大小密切相关。不同交换度的HZSM-5上酯化反应稳定性的实验结果进一步证明,烯烃的聚合结焦主要是在强酸中心上进行的。C_1—C_6脂肪醇用乙酸酯化的结果表明,在酯化反应的条件下,C_1—C_2醇不生成烯烃,三个碳以上的伯醇付产少量烯烃,而仲醇和叔醇主要转化为烯烃。在HZSM-5上环状化合物的酯化反应表明,苄醇和乙酸、苄醇和已酸、环已醇和乙酸都可以比较顺利地进行酯化反应。由于空间效应的影响,苯甲酸与正丁醇的酯化比较难于进行。
The ion exchange degree of HZSM-5, the reaction conditions and the influence of the structure of reactants on the catalytic performance were discussed. It was experimentally found that there was a rapidly increasing turning point in the catalytic activity at ion exchange degrees of 60% (esterified with acetic acid and ethanol) and 70% (esterified with acetic acid and n-butanol), respectively. This phenomenon is closely related to the strength of the acid sites on the zeolite surface and the size of the reactant molecules. Experimental results on the esterification reaction stability of HZSM-5 with different exchange degrees further prove that the polymerization coking of olefins is mainly carried out on strong acid sites. The results of esterification of C 1 -C 6 fatty alcohols showed that under the conditions of esterification, C 1 -C 2 alcohols did not produce alkenes, while those with more than 3 carbons yielded few alkenes, while the secondary and tertiary alcohols were mainly converted to Olefin. Esterification of cyclic compounds on HZSM-5 showed that benzyl alcohol and acetic acid, benzyl alcohol and hexanoic acid, cyclohexanol and acetic acid all performed relatively smoothly. Esterification of benzoic acid with n-butanol is more difficult to carry out due to the spatial effect.