硅铝摩尔比对MCM-22的酸性及苯与丙烯烷基化催化性能的影响  

Effects of n(SiO_2)/n(Al_2O_3) in MCM-22 acid properties and catalysis in alkylation of benzene with propylene

作　　者：陈亮[1] 李英霞[1] 陈标华[1] 李成岳[1] 曹钢 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,北京100029 [2]北京燕山石油化工股份有限公司化学品事业部,北京102500

出　　处：《北京化工大学学报（自然科学版）》2004年第6期18-23,共6页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：国家重点基础研究发展规划项目 (G2 0 0 0 0 4 80 0 6 )

摘　　要：以六亚甲基亚胺为模板剂 ,通过动态水热晶化法合成硅铝摩尔比为 2 0～ 6 0的分子筛 ,采用XRD表征其物相结构 ;并采用NH3 TPD ,吡啶吸附等方法表征其酸性质 ;利用气 液 固反应和液 固反应 ,比较不同硅铝摩尔比的MCM 2 2分子筛在苯与丙烯烷基化反应的催化性能。结果表明 :当硅铝摩尔比在 30～ 6 0时 ,可以合成出比较纯的MCM 2 2分子筛 ,且随着硅铝摩尔比的增加 ,分子筛的B酸量逐渐增加 ,所表现出的烷基化活性也随之增加。当硅铝摩尔比为 4 0时 ,目标产物异丙苯的选择性达最高值 ,副产物二异丙苯和三异丙苯的摩尔分数最低 ,但正丙苯的摩尔分数却最高 ,这与催化剂中B酸量及其所占比例有关。Molecular sieve with n(SiO 2)/n(Al 2O 3) ratios of 20～60 were hydrothermally synthesized with hexamethyleimene used as template. The synthesized zeolites were characterized by XRD. The acidity properties of the synthesized zeolites were investigated by means of NH 3-TPD and Pyridine-IR. The catalytic performance of the synthesized zeolites was also studied in alkylation of benzene with propylene. The experimental results show that (1) MCM-22 molecular sieve can be synthesized as purer phase in n(SiO 2)/n(Al 2O 3) from 30 to 60,(2) with increasing n(SiO 2)/n(Al 2O 3), the Bronsted acid amount of MCM-22 molecular sieve is increased. The catalytic activity of MCM-22 molecular sieve is increased too, and (3) when the n(SiO 2)/n(Al 2O 3) is equal to 40, the selectivity of cumene is the highest, and the amount of di-isopropylbenzene and tri-isopropylbenzene in cumene is the lowest, however, the amount of n-propylbenzene is the highest. The catalytic performance was correlated with the Bronsted acid amount and its proportion of MCM-22 molecular sieve.

关 键 词：MCM-22分子筛 硅铝摩尔比 酸性质 催化性能 

分 类 号：O643.36[理学—物理化学] TQ426.95[理学—化学]