关键词: ZSM-5分子筛, 整体催化剂, 原位水热合成法, 甲苯甲醇烷基化, 二甲苯

Abstract: 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.

Key words: ZSM-5 zeolite, monolith catalyst, in-situ hydrothermal synthesis, alkylation of toluene and methanol, xylene