用于苯酚与异丙醇烷基化反应的分子筛催化剂

Molecular Sieve Catalysts in Alkylation of Phenol with Isopropanol

研究了HZSM-5,HMCM-49,HMCM-41分子筛催化苯酚与异丙醇烷基化反应的性能,采用X射线衍射和NH3程序升温脱附等方法对分子筛进行了表征。实验结果表明,反应温度、分子筛的酸强度和酸量以及孔道结构是影响分子筛催化苯酚与异丙醇烷基化反应性能的重要因素,反应结果是各种因素共同作用的结果。以酸强度高、酸量多的微孔HZSM-5分子筛为催化剂,烷基化反应的主要产物为对异丙基苯酚,但其催化活性和稳定性相对较差;以中等酸量、超笼结构的HMCM-49分子筛为催化剂,低温时烷基化反应的主要产物为邻异丙基苯酚,高温时烷基化反应的主要产物为对异丙基苯酚,且HMCM-49分子筛有较高的催化活性及稳定性;以低酸量、中等酸强度的中孔HMCM-41分子筛为催化剂,其催化活性与稳定性都较差,且有较多的O-烷基化产物生成。

Alkylation of phenol with isopropanol was carried out on three different kinds of molecular sieve catalysts, HZSM-5, HMCM49 and HMCM-41. The difference in performances of the three molecular sieve catalysts was investigated from viewpoint of superficial acid strength, acid amount and pore structure. Reaction temperature was another main factor that affected the alkylation. On microporous HZSM-5 molecular sieve with high acid strength and large acid amount the main alkylation product is p-isopropylphenol, but the activity and stability of HZSM-5 are low. On supercage HZSM-49 molecular sieve with medium acid strength and medium acid amount the main product is O-isopropylphenol at low temperature and p-isopropylphenol at high temperature. Both activity and stability of HZSM-49 are promising. On HMCM-41 molecular sieve with medium acid strength and low acid amount the selectivity to O-alkylation products is relatively high, but its activity and stability are untolerable.