Abstract: Five kinds of Si/Al ratio ZSM-5 zeolites with small particle size and hierarchical pore were prepared by simple in-situ hydrothermal methods. XRD, N₂ adsorption-desorption, NH₃-TPD, Py-IR and SEM were used to characterize the prepared ZSM-5. The catalytic performance of ZSM-5 Zeolites with different Si/Al ratio for benzene/methanol alkylation was investigated. The results showed that the ZSM-5 zeolites with different Si/Al ratio had multi-stage pore structure, irregular particle shape, small crystal size and honeycomb shape. Under the conditions of 470 ℃, 0.5 MPa (H₂) and space velocity 2 h-1, n(methanol): n(benzene)=1:1, the alkylation of benzene with methanol catalyzed by ZSM-5 zeolites with different Si/Al ratio was studied. The results showed that the conversation of benzene was 62.92%, the selectivity of xylene was 37.38%, and the selectivity of ethylbenzene 0.81% when n(SiO₂)/n(Al₂O₃) was 150 and the reaction time was 72 h. The ZSM-5 still has good activity after 1 200 h operation and has a good application prospect.

Key words: Si/Al ratio, small particle size, hierarchical, ZSM-5, alkylation