Nu88分子筛的合成、表征及在甲苯甲醇烷基化中的催化性能

SYNTHESIS,CHARACTERIZATION OF ZEOLITE Nu88,AND ITS CATALYTIC PROPERTIES IN TOLUENE ALKYLATION WITH METHANOL

采用水热法合成了Nu88分子筛。考察了不同硅源、铝源和模板剂(SDA)对分子筛合成的影响;采用XRD、BET、SEM、NH3-TPD、Py-IR、29Si MAS NMR、27Al MAS NMR等手段对分子筛进行表征,并考察其在甲苯甲醇烷基化反应中的催化性能。结果表明,碱性硅溶胶为硅源、NaAl O2为铝源时,采用1,6-双(N-甲基吡咯烷己烷)溴盐和1,5-双(N-甲基吡咯烷戊烷)溴盐为模板剂均能合成出Nu88分子筛;该分子筛为纳米晶体,具有良好的热稳定性,酸性较弱;其催化性能与β分子筛相似,推测其属于多维、大孔沸石范畴。

Nu88 zeolite was synthesized by hydrothermal method.The effects of silica source,alumina source and structure direction agent（SDA） on the synthesis of Nu88 were investigated.The synthesized Nu88 zeolite was characterized by XRD,BET,SEM,NH3-TPD,Py-IR,29Si MAS NMR,27Al MAS NMR,and its catalytic performance in the reaction of toluene alkylation with methanol was evaluated.The results showed that Nu88 could be synthesized with 1,5-bis（N-methylpyrrolidinium）pentane or 1,6-bis（N-methylpyrrolidinium）hexane as structure direction agent,alkaline silicasol and NaAlO2 as the silica source and alumina source,respectively.The synthesized Nu88 zeolite was a nanocrystalline material,and had high thermal stability and weak acid sites.It can be induced from the similar catalytic properties of Nu88 with β that Nu88 is a multidimensional and large-pore zeolite.