论文部分内容阅读
ＴＰＤ研究表明，焙烧温度为５００℃时，Ｈβ沸石表面酸量最大，高于或低于这个温度，表面酸量都下降，而酸的强度始终随焙烧温度的升高而增强．在环己烯与乙酸的加成反应中，该沸石催化剂活性与酸量的变化规律相一致，但选择性随酸强度的增加而下降．用ＧＣ－ＩＲ对反应的副产物进行了研究，探讨了催化剂失活的机理，证明了２－环己烯酮、２－环己烯基环己酮等羰基化合物是催化剂致毒物．同时考察了反应时间、温度及酸／烯摩尔比对反应的影响．结果表明，酸／烯摩尔比为５．５：１．在１００℃和自生压力下反应４ｈ，环己烯的转化率可达８４％左右，乙酸环己酯的选择性可达９０％以上．
The results of TPD showed that the surface acidity of Hβ zeolite was the highest when the calcination temperature was 500 ℃. The acidity of the surface of Hβ zeolite decreased at or above this temperature, while the acid strength always increased with the calcination temperature. In the addition reaction of cyclohexene with acetic acid, the activity of the zeolite is consistent with the change of acidity, but the selectivity decreases with the increase of acid strength. The by-products of the reaction were studied by GC-IR, and the mechanism of catalyst deactivation was discussed. It was proved that carbonyl compounds such as 2-cyclohexenone and 2-cyclohexenylcyclohexanone were catalyst poison. The effects of reaction time, temperature and acid / alkene molar ratio on the reaction were also investigated. The results showed that the acid / alkene molar ratio was 5.5: 1. At 100 ℃ and autogenous pressure for 4h, the conversion of cyclohexene can reach about 84%, and the selectivity of cyclohexyl acetate can reach more than 90%.