Cocrystalline Synthesis of ZSM-5/ZSM-11 and Catalytic Activity for Methanol to Propylene

Cocrystalline ZSM-5/ZSM-11 zeolite is hydrothermally synthesized at crystallization temperatures of 170 and 130 degrees C, respectively, in order to regulate the acidity as well as the framework Al distribution to enhance the propylene formation from methanol. ZSM-5/11-170 has analogous textural properties to ZSM-5 but with increased strong Bronsted acid amount, raising the propylene selectivity by 49% in the methanol to propylene reaction at 480 degrees C, attributed to the increasing Al distribution in the straight channels by introduction of ZSM-11 into ZSM-5. With crystallization to 130 degrees C, the strong Bronsted acid amount of ZSM-5/11-130 is decreased by 82% compared with ZSM-5/11-170. The selectivity of propylene is increased to 38.25%, along with the decrease in the selectivity of ethylene and C-5-C-9.