不同模板剂制成的β沸石对苯与丙烯烷基化反应的影响

Samples (F-β and W-β) of zeolite-β synthesized by different templates were characterized by XRD, TPD and pore structure analysis. The differences of the zeolite-βsynthesized by two templates have been investigated through the activity evaluation of benzene alkylation reaction and the experiment of accelerated-aging. Coke composition on the deactivated catalysts used in industrial process and accelerated-aging experiment process was analyzed by MS-GC. The result shows that the two processes are similar in deactivation process of catalysts. Main coke materials are multi-aromatic hydrocarbons, which are deepening products of diisoproplbenzene alkylation. They can not diffuse from the pore of the zeolite easily, and block the pore path, and occupy the activity sites. Thus it makes the catalyst deactivated. Steric constraints during the formation of coke molecules are more pronounced in the relatively narrow cages than in the large cages. Because difference of pore distribution between F-βand W-βsamples, F-βsample has more the narrow cages (or more micropore) than W-βsample, and it has stronger steric constraint during deepening alkylation of disoproplbenzene than W-βsample, and lower coke is formatted on F-βsample. This reason results in better stability of the F-βsample. The pore structure data show that rational distribution of micropore in zeolite-βis very important to restrain producing of the coking materials. Different distribution of pore on zeolite-βis the main reason that makes F-βand W-βsamples have differences in the activity evaluation of alkylation reaction and stability of the accelerated-aging experiment.