Preparation of ZSM-5-SBA-15 composite molecular sieves and its performance for toluene alkylation with methanol

A series of ZSM-5-SBA-15 composite molecular sieves were prepared by post-synthesis method and characterized by XRD, FT-IR, BET, NH₃-TPD and pyridine infrared. The results indicated that ZSM-5-SBA-15 has both ZSM-5 microporous and SBA-15 mesoporous structure. The adsorption-desorption measurement using pyridine and ammonia demonstrated that acidity of SBA-15 was heightened because ZSM-5 was introduced into. Compared with ZSM-5, the acidic sites on ZSM-5-SBA-15 were still accessible. However, the strength of acidity was weakened. In the probe reaction of the alkylation of toluene and methanol, the ZSM-5-SBA-15 composite exhibited higher para-xylene selectivity in comparison to pristine ZSM-5.