Methanol converting to propylene on weakly acidic and hierarchical porous MFI zeolite

H-B,Al-ZSM-5 zeolites were synthesized with glucose as assistant template to catalyze methanol converting toward propylene. The superior catalytic performance in terms of the propylene selectivity and the activity longevity was related to high ratio of weak acid to strong acid for favorable production of propylene and to high mesoporosity for improved diffusion of reactants and prevention from fast coking. More framework Al siting in the straight or sinusoidal channels of the MFI zeolite could also enhance the propylene/ethylene ratio due to the promotional effect on propylene formation. Low weak acid density was conducive to the production of high propylene/ethylene ratio. With the B/Al ratio of 2 and the (Al₂+B₂)/Si ratio of 0.01, HZ5-G-2B was applied in the methanol to propylene reaction at CH₃OH/H₂O (1∶1.2) WHSV of 1.8 h⁻¹ and 480 °C. Propylene selectivity of 51.6%, the \rmC_2-4^ = selectivity of 83.7% and complete conversion of methanol were achieved. The propylene/ethylene ratio was 2. The catalytic activity kept stable for 580 h.