机构地区:[1]College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032,China [2]College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032,Chinahe liquid phase alkylation of catechol with tert-butyl alcohol to produce 4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite and novel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is the main product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the side products. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBC compared to other solid acid catalysts tested. Over the PMHs derived from H-exchanged montmorillonite through template extraction processes, the suitable reaction temperature is ca 410 K, the ratio of catechol to iert-butyl alcohol is 1:2. Increasing the amount of catalyst (lower weight hourly space velocity) can improve the conversion of catechol and influence the selectivity slightly. The reasonable reaction time is ca 8 h. The type and strength of acidity of H-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammonia temperature-programmed desorption techniques. The medium and strong acid sites are conducive to producing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences between the PMHs from calcination and those from extraction are attributed to proton migration and acidity change in the gallery surface.
出 处:《Chinese Journal of Chemical Engineering》2004年第3期388-394,共7页中国化学工程学报(英文版)
基 金:Supported by the National Natural Science Foundation of China (No. 20376075); the Natural Science Foundation of Zhejiang Province (No. 201057).
摘 要:The liquid phase alkylation of catechol with tert-butyl alcohol to produce4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite andnovel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is themain product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the sideproducts. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBCcompared to other solid acid catalysts tested. Over the PMHs derived from H-exchangedmontmorillonite through template extraction processes, the suitable reaction temperature is ca 410K, the ratio of catechol to tert-butyl alcohol is 1:2. Increasing the amount of catalyst (lowerweight hourly space velocity) can improve the conversion of catechol and influence the selectivityslightly. The reasonable reaction time is ca 8 h. The type and strength of acidity ofH-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammoniatemperature-programmed desorption techniques. The medium and strong acid sites are conducive toproducing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences betweenthe PMHs from calcination and those from extraction are attributed to proton migration and aciditychange in the gallery surface.The liquid phase alkylation of catechol with tert-butyl alcohol to produce 4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite and novel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is the main product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the side products. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBC compared to other solid acid catalysts tested. Over the PMHs derived from H-exchanged montmorillonite through template extraction processes, the suitable reaction temperature is ca 410 K, the ratio of catechol to tert-butyl alcohol is 1:2. Increasing the amount of catalyst (lower weight hourly space velocity) can improve the conversion of catechol and influence the selectivity slightly. The reasonable reaction time is ca 8 h.The type and strength of acidity of H-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammonia temperature-programmed desorption techniques. The medium and strong acid sites are conducive to producing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences between the PMHs from calcination and those fi'om extraction are attributed to proton migration and acidity change in the gallery surface.
关 键 词:ALKYLATION CATECHOL 4-tert-butyl catechol porous montmorilloniteheterostructures solid acid catalysts ACIDITY
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