Cationic polyelectrolyte stimulated ultrafast synthesis of hierarchical ZSM-11 zeolite with improved methanol to olefin catalytic performances

Rapid and precise crystallization of zeolites with targeted topologies remains a significant challenge. Herein, we report a facile strategy for synthesizing ZSM-11 within 12 h by introducing cationic poly(dimethyl diallyl ammonium chloride) (PDDA) into the precursor gels. This approach achieves an 80-fold acceleration versus conventional methods while yielding nanosized crystals with hierarchical pore architectures. We demonstrate that unique confined nano-interfaces/nano-microenvironment formed via electrostatic assembly of cationic PDDA and negatively charged silica precursors facilitate enrichment of crystallization nutrients, e.g. tetrabutylammonium hydroxide, water, and silica/alumina species. This unique confined nano-interfaces/nano-microenvironment promotes in-situ depolymerization-condensation reactions of the silica/aluminum species and shortens nutrient transport pathways, collectively accelerating nucleation and crystallization. The mechanism is further supported by the comparative experiments via changing synthesis parameters including PDDA(C 8 H 16 NCl)/SiO 2 ratio, polymerization degree of PDDA, and addition of silicalite-2 seeds. The rapidly synthesized ZSM-11 exhibits superior methanol-to-olefins (MTO) performance, demonstrating tremendously extended catalyst lifetime and high coke resistance relative to conventionally prepared counterparts. This work advances a generalizable route to efficient synthesis of zeolite catalysts.