High-Efficiency Synthesis of Uniform Nanosized ZSM-5 Zeolite for Enhanced Methanol-to-Propylene Reaction

The performance of zeolites can be strongly influenced by their morphologies and internal porous structure. Due to the low premixing efficiency of precursor mixture solutions during conventional zeolite synthesis, it is difficult to synthesize a uniform ZSM-5 zeolite. In this study, we report a rapid and highly efficient method for synthesizing uniform nanosized ZSM-5 zeolite using a hydrothermal approach facilitated by a microliquid-film reactor (MLFR), without the addition of crystal seeds. The results demonstrated that the MLFR significantly improved the micromixing of high-viscosity zeolite precursor mixture solutions in a short duration, thereby substantially accelerating the subsequent silicon source hydrolysis, polycondensation, nucleation, and crystal growth processes during ZSM-5 zeolite synthesis. Compared to ZSM-5 zeolite synthesized by the traditional hydrothermal method using a mechanical stirring tank, the MLFR-derived ZSM-5 zeolite exhibited smaller particle size, improved crystallinity, higher specific surface area, excellent hydrothermal stability, and a more developed pore structure. Notably, the MLFR-derived ZSM-5 zeolite achieved a high propylene selectivity of approximately 55.08%, an unprecedentedly high selectivity of light olefins (89.92%), and a long catalytic life of 126 h in the methanol-to-propylene (MTP) reaction, mainly attributable to the increased accessibility of acid sites and the reduced diffusion pathways in smaller ZSM-5 zeolite particles. This study offers a promising strategy for the high-efficiency synthesis of uniform nanosized ZSM-5 zeolite and provides a deeper understanding of the enhanced catalytic performance of ZSM-5 zeolites in the MTP reaction.