原位水热合成ZSM-5/堇青石整体催化剂及其对甲苯、甲醇烷基化的催化性能

以蜂窝状堇青石为载体，采用原位水热合成法制备ZSM-5/堇青石整体催化剂，采用XRD和SEM等手段对其进行表征，考察模板剂四丙基氢氧化铵（TPAOH）用量、硅铝比和晶化时间等因素对ZSM-5分子筛在堇青石载体表面生长的影响，并评价其对甲苯、甲醇烷基化反应的催化性能。结果表明：通过调节TPAOH用量、硅铝比、晶化时间等条件，可有效控制ZSM-5在堇青石表面的生长；不同硅铝比的ZSM-5在堇青石表面生长的差异较大，而通过调节TPAOH用量可有效控制ZSM-5在载体表面的负载量和晶体颗粒直径；与ZSM-5粉末催化剂相比，ZSM-5/堇青石整体催化剂上的甲苯转化率降低，而对二甲苯选择性提高；随着硅铝比增大，ZSM-5/堇青石整体催化剂上的甲苯转化率降低，而对二甲苯选择性提高。

IN-SITU HYDROTHERMAL SYNTHESIS OF ZSM-5/CORDIERITE MONONLITH CATALYSTS AND THEIR CATALYTIC PERFORMANCE OF TOLUENE ALKYLATION WITH METHANOL

ZSM-5/cordierite monolith catalysts were synthesized by in-situ hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The effects of the template dosage of tetra-propyl ammonium hydroxide (TPAOH), n(SiO2)/n(Al2O3) ratio and crystallization time on the growth of ZSM-5 on cordierite supporter were investigated and the performance of catalysts for alkylation of toluene and methanol was tested. The results reveals that different growth on the support are found for ZSM-5 zeolites with different Si/Al ratios, the above factors can effectively control the growth of ZSM-5 zeolites on cordierite surface. The load and crystal size of ZSM-5 on supporter surface can be adjusted effectively by the amount of TPAOH. Compared with the ZSM-5 powder samples, the toluene conversion on monolithic samples is lower but higher in selectivity of para-xylene. With the increase of n(SiO2)/n(Al2O3) ratio in monolithic catalysts, the conversion of toluene reduces and xylene selectivity increases.