Organosilane Surfactant-Directed Synthesis of Hierarchical ZSM-5 Zeolites with Improved Catalytic Performance in Methanol-to-Propylene Reaction

The hierarchical ZSM-5 zeolites with interconnected meso-/microporosity have been successfully synthesized by using the commercial organosilane surfactant TPOAC as the mesopore structure-directing agent, and the influence of the TPOAC/SiO2 ratio in the initial synthesis gel on the crystallinity, hierarchical structure, and acidity of the obtained hierarchical ZSM-5 zeolites were systematically investigated through a combination of XRD, FTIR, SEM, TEM, N-2 adsorption, TGA, ICP, and NH3-TPD techniques. The catalytic performance was evaluated by the methanol-to-propylene (MTP) reaction, and the obtained results indicated that the hierarchical ZSM-5 catalysts directed by TPOAC exhibited significant enhancement in the catalytic performance reflected at activity, lifetime, product yield, P/E ratio, and coke toleration by virtue of their superior meso-/micropore interconnectivity and appropriately weakened acidity, comparing with the commercial bulky ZSM-5 and the conventional sole micropore ZSM-5.