改性HUSY沸石上β-甲基萘异丙基化反应性能研究

Study of isopropylation of β-methylnaphthalene with isopropanol over modified HUSY zeolites

采用HUSY沸石分子筛催化了β-甲基萘与异丙醇的烷基化反应，在未改性HUSY沸石催化下，β-甲基萘转化率可达74．4％．考查了碱土金属氧化物改性对HUSY沸石分子筛表面酸性和催化性能的影响，通过NH3-TPD表征发现，改性后HUSY沸石的弱酸中心量基本不变，而中强酸与强酸中心量下降，导致催化活性下降，甲基异丙基萘与β-甲基-6-异丙基萘的选择性上升．研究了镁浸溃量对催化性能的影响以及改性前后催化剂的稳定性和再生性能．浸渍量为2％～3％为适宜的用量；镁改性HUSY沸石分子筛具有较好的甲基异丙基萘和2-甲基-6-异丙基萘选择性，稳定性好，再生能力强，是β-甲基萘异丙基化反应较为理想的催化剂．

The liquid phase alkylation of β-methylnaphthalene over HUSY zeolites has been investigated using isopropanol as the alkylating agent. HUSY zeolites without modification perform good catalytic activities and 74. 4% conversion of 13-methylnaphthalene is obtained. The effects of different alkali earth metal oxides on the acidity and catalytic performance are studied. The results of acidity of modified zeolites using NH3-TPD show that the weak acid sites keep fixed at the same time, and that the moderate strong acid sites and strong acid sites reduce, which results in the decrease of catalytic activities and the increase of selectivities for methylisopropylnaphthalene and 2-methyl- 6-isopropylnaphthalene. The influence of MgO content and the stability and regeneration capability of HUSY catalysts before and after modification are also investigated. The proper content of MgO is 2%-3%. HUSY zeolites modified by MgO, which perform not only good selectivities towards methylisopropylnaphthalene and 2-methyl-6-isopropylanphthalene but favorable stability and regeneration capability, is found to be a proper catalyst for isopropylation of β-methylnaphthalene with isopropanol.