纳米级MCM-49分子筛催化苯与1-十二烯烷基化反应的性能  

Catalytic Performance of Nanometer MCM-49 Zeolite for Alkylation Reaction of Benzene with 1-Dodecene

作　　者：李工[1] 阚秋斌[1] 佟惠娟[2] 吴通好[1] 许宁[1] 吴鹏[1] 王东阳[1] 

机构地区：[1]吉林大学化学学院,吉林长春130023 [2]江苏工业学院化学工程糸,江苏常州213016

出　　处：《催化学报》2004年第10期809-813,共5页

基　　金：国家自然科学基金资助项目 ( 2 0 2 73 0 2 5 )

摘　　要：在低碱度下合成了纳米级MCM 4 9分子筛 ,采用XRD ,TEM ,NH3 TPD ,吸附吡啶的红外光谱和异丙苯裂解等技术对分子筛进行了表征 .催化剂评价结果表明 ,纳米级MCM 4 9分子筛在 30～ 16 0℃下对苯与 1 十二烯的烷基化反应具有良好的催化性能 ,烯烃的转化率高于 99 6 % ,直链烷基苯的选择性大于 97% ,2 和 3 位直链烷基苯的选择性大于 6 7 5 % .常规的微米级MCM 4 9分子筛在低温下的催化活性低于纳米级MCM 4 9分子筛 .ZSM 5 ,M型分子筛和MCM 4 1分子筛催化烷基化反应的活性较低 ,Y型分子筛虽具有较高的催化活性 ,但生成 2 和 3 位直链烷基苯的选择性明显低于MCM 4 9.MCM 4 9的骨架结构与MCM 2 2相似 ,晶体外表面上含有大量的 12元环孔穴 ,该结构有利于烷基化反应的进行 .Nanosize MCM-49 zeolite was synthesized under low alkalinity, and it was characterized by XRD, TEM, NH 3-TPD, IR spectra of adsorbed pyridine and cumene cracking techniques. The shape of synthesized MCM-49 was of a sheet-like hexagonal structure with diameter of 300～500 nm and thickness of 20～25 nm. The TPD result showed that HMCM-49 contained both strong acid sites and weak acid sites, and IR spectra of adsorbed pyridine confirmed that the zeolite contained Lewis acid together with Brnsted acid. The total acid amount of nanosize and micrometer MCM-49 was 1.30 and 1.28 mmol/g, respectively. Nanometer MCM-49 showed high activity and selectivity for the alkylation reaction of benzene with 1-dodecene in the temperature range of 30～160 ℃, the conversion of 1-dodecene was higher than 99.6%, the selectivity for linear alkylbenzene (LAB) was more than 97%, the selectivity for 2- and 3-LAB was over 67.5%. The catalytic activity of micrometer MCM-49 was lower than that of nanometer MCM-49 at low temperature. ZSM-5, M and MCM-41 zeolite exhibited poor activity and selectivity for the alkylation reaction, and Y zeolite displayed high activity but low selectivity for 2- and 3-LAB. The framework topology of MCM-49 was similar to the calcined MCM-22 and contained 12-ring channels on the external surface of the hexagonal plates, which played an important role in improving the activity and selectivity for the alkylation reaction.

关 键 词：纳米 MCM-49分子筛 合成 酸性 苯 1-十二烯 烷基化 

分 类 号：O643[理学—物理化学]