Abstract: The magnesium-modified hierarchical porous ZSM-5 catalysts with different magnesium loadings were prepared and characterized by XRD, N₂ adsorption-desorption and NH₃-TPD. The effects of reaction temperature, mass space velocity, raw material ratio and magnesium loading on the performance of magnesium-modified ZSM-5 catalyst for the alkylation of benzene with methanol were investigated. The results showed that the optimal process conditions for the alkylation of benzene with methanol over Mg-modified ZSM-5 catalyst covered a reaction temperature of 470℃, a mass space velocity of 2.0 h^-1,and a molar ratio of benzene to methanol of 1∶1. The modified ZSM-5 catalyst with 3% magnesium loading (w) could run continuously for 1300h with the average conversion of benzene over 54%, the average selectivity of toluene and xylene over 90%, and the average selectivity of ethylbenzene below 1.5%. The activity and stability of the regenerated catalyst was similar to that of the fresh catalyst. The catalyst had been tested and verified by industrial experiments, and showed the prospect of industrial application.

Key words: ZSM-5 Molecular Sieve, Magnesium, Benzene, Methanol, Alkylation