Direct and Selective Gas-phase Hydration of Lower Olefin to Alcohol and Ketone

本文研究了低烯烃在质子交换沸石催化剂上汽相或液相的直接水化反应，并观察到了以下现象。丙烯、l-烯和异丁烯气相水化反应中，异丁烯的反应活性最高。在383 K时，叔丁醇的收率约为20%。SIO_2/Al_2O_3 = 15 ~ 20的沸石水化活性最强。另一方面，发现丙烯或l-丁烯在超稳定y型沸石（HUSY）上进行水合脱氢反应生成丙酮或甲基乙基酮。人们一直在努力开发更有活性的酮生成催化剂，目前认为CAO/HUSY是最好的催化剂。研究了异丁烯在常压和高压条件下的液相水化反应。质子分子筛的活性和选择性都很高。例如，H-ZSM-5在383 K、1.5 atm和30 min条件下，对叔丁醇的转化率和选择性分别为50%和95%。沸石的催化活性与铝的含量有关；al含量越少的沸石活性越高。结果表明：首先，质子分子筛是一种较好的催化剂，比其他催化剂如P_2O_5/SiO_2和离子交换树脂更好；其次，在丙烯-丁烯混合物的水化反应中，质子分子筛可以选择性地得到叔丁醇。

Direct hydration of lower olefins on proton-exchanged zeolite catalysts has been studied in vapor or liquid phase and the following have been observed.1. In gas-phase hydration of propylene, l-btene, and iso-butene the reactivity of iso-butene was the highest. The yield of tert-butanol amounted to ca. 20% at 383 K. The zeolites with SIO_2/Al_2O_3 = 15-20 were the most active for the hydration. On the other hands, hydrative dehydrogenation of propylene or l-butene to give acetone or methyl ethyl ketone was found to proceed on ultra-stable Y-type zeolites(HUSY). Effort has been devoted to develop more active catalyst for the ketone formation and CAO/HUSY was concluded to be the best at the present.2. Liquid-phase hydration of iso-butene has been studied under both atmospheric pressure and high pressure. The activity and selectivity of the proton-zeolites were very high. For example, the conversion and selectivity to tert-butanol were 50% and 95%, respectively, on H-ZSM-5 at 383 K, 1.5 atm, and 30 min. The catalytic activity of the zeolites was dependent on the aluminum content; the zeolites with less amount of al showed higher activity.The results strongly suggest first that the proton-zeolites are better catalysts that other catalysts such as P_2O_5/SiO_2 and ion exchange resin, secondly than one might be able to get selectively tert-butanol in hydration of mixture of propylene and butenes.