Catalytic study for methanol aromatization over hierarchical ZSM-5 zeolite synthesized by kaolin

Hierarchical and conventional ZSM-5 zeolites were synthesized through steam-assisted crystallization approach using acid-treatment kaolin clay as the silica and aluminium sources. The samples were characterized by XRD, SEM, NH3-TPD, N-2-physisorption and TG techniques. The results showed that hierarchical ZSM-5 had rich mesopores and bigger specific surface. In conversion of methanol to aromatics, hierarchical and conventional ZSM-5 zeolites showed higher selectivity for aromatics compared with commercial ZSM-5. Under the conditions of 450 degrees C, 0.15MPa, the synthesized hierarchical ZSM-5 showed longest lifetime of 380h, which was 2 and 6times than those of conventional and commercial ZSM-5, respectively.