不同方法合成的HZSM-5分子筛上苯胺与异丙醇烷基化反应规律的研究

考察了通常条件处理（８２３Ｋ焙烧）及高温焙烧和水蒸气处理后直接法和有机胺法合成的ＨＺＳＭ－５分子筛上苯胺与异丙醇的烷基化反应，发现通常条件处理的有机胺法合成的ＨＺＳＭ－５分子筛反应活性及对异丙基苯胺的选择性较直接法合成ＨＺＳＭ－５分子筛高。高温焙烧及水蒸气处理后，两种不同方法合成的ＨＺＳＭ－５分子筛烷基化性能呈现不同的变化规律：直接法合成的ＨＺＳＭ－５分子筛随处理温度的提高，对异丙基苯胺的选择性提高，苯胺转化率升高，并有一最佳处理温度；有机胺法合成的ＨＺＳＭ－５分子筛随处理温度的提高，苯胺转化率降低，处理温度过高，对异丙基苯胺的选择性降低。以ＢＥＴ重量法测定ＨＺＳＭ－５分子筛的环己烷吸附量表征其孔径，用ＮＨ３－ＴＰＤ，吸附吡啶ＩＲ方法表征催化剂表面酸性质，发现两种不同方法合成的ＨＺＳＭ－５分子筛烷基化性能的不同是二者酸性质、孔径及骨架铝稳定性的不同所致

STUDY ON ALKYLATION OF ANILINE WITH ISOPROPANOL ON HZSM 5 SYNTHESIZED BY DIFFERENT METHODS

The alkylation of aniline with isopropanol to synthesize para isopropylaniline( p IPA)has been studied on HZSM 5(synthesized with or without organic template).Calcination and hydrothermal treatment were adopted to treat HZSM 5.The properties of catalysts were evaluated in the fixed bed flow reactor under atmospheric pressure.The surface acidity was measured by means of NH 3 TPD and pyridine adsorbed IR.The relative pore size of HZSM 5 zeolite was determined by cyclohexane adsorbance. In normal treatment condition(calcination at 823K),the aniline conversion and the selectivity of p IPA on HZSM 5 synthesized with template were higher than those on HZSM 5 without template,as the former afforded proper acidity and larger pore size. After high temperature calcination or hydrothermal treatment,HZSM 5 zeolite synthesized by different methods exhibited different reactivities in alkylation.With the treatment temperature increased,on the HZSM 5 synthesized with template the aniline conversion decreased,the selectivity of p IPA declined when treatment temperature was very high;while on HZSM 5 synthesized without template the selectivity of p IPA increased,the aniline conversion rose first and then dropped slowly,which was due to their differences in acid strength,acid distribution,pore size distribution and the stability of framework aluminum. The main active centers on HZSM 5 for synthesis of IPA were Brnsted acid with proper strength,while Lewis acid played a subsidiary role.