Transformation of methanol to trimethylbenzene catalyzed by cadmium modified HZSM-5 zeolites

Cadmium-modified HZSM-5 zeolite (Cd/HZSM-5) was prepared by ultrasound-assisted impregnation and its catalytic performance for methanol to aromatics (MTA) was investigated. It was characterized by means of XRD, SEM, TEM, Py-IR, N2 adsorption/desorption, NH3-TPD and XPS. Cd species distribute in the surface of the HZSM-5 zeolite, decreasing the crystallinity and increasing the Lewis acidity strength. Under the operating reaction condition of temperature at 400 °C, pressure at 0.1 MPa and space velocity of 1.896 h−1, 1.4 wt% Cd/HZSM-5 zeolites showed good catalytic activity for MTA with the aromatic’s selectivity of 71.1%. Compared with that of about 7.5% over HZSM-5, the trimethylbenzene isomers in aromatics is 86.6% and the main product is 1,2,4-trimethylbenzene with selectivity of 34.0% in all products and 86.5% in trimethylbenzene isomers over 1.4 wt% Cd/HZSM-5 zeolites.