HZSM-5/AlPO_4-5复合分子筛的合成及其甲苯甲醇烷基化择形催化性能研究

Synthesis of HZSM-5/AlPO_4-5 cmposite molecular sieves and their selective catalytic performance in alkylation of toluene with methanol

采用水热法在AlPO_4-5的合成母液中引入HZSM-5,制备了一系列不同固液比、不同晶化时间的HZSM-5/AlPO_4-5复合分子筛,采用XRD、SEM、FT-IR和NH3-TPD等手段对分子筛的微观结构进行表征,考察其在甲苯甲醇烷基化催化中的活性。结果表明:在固液比为1g/30m L、晶化时间72h的HZSM-5/AlPO_4-5复合分子筛结晶度以及壳层致密度较高,外表面强酸量较小,与HZSM-5分子筛相比,对二甲苯选择性明显提高。

HZSM-5/AlPO4-5 composite molecular sieves were synthesized by using hydrothennal method and introducing HZSM- 5 as core materials to mother liquid of AlPO4-5 under different solid to liquid ratios and crystallizing time, and characterized by XRD, SEM, FT-IR and NH3-TPD. Catalytic performances of the HZSM-5/AlPO4-5 catalysts for alkylation of toluene with methanol were investigated. The results show that HZSM-5/AlPO4-5 composite molecular sieves with high crystallinity could be obtained when the ratio of solid to liquid is 1 g to 30 mL and the crystallizing time is 72h, and the selectivity of p-xylene over the HZSM-5/AlPO4-5 was obviouly higher than that over the pure HZSM-5.