ZSM-48 zeolites with controllable mesopore formation: synthesis, characterization, and catalytic performance

The creation of mesopore through desilication method is often followed by excessive silica dissolution, especially in high silica zeolite like ZSM-48, leading to crystal destruction. Herein, the mesopore was successfully generated through desilication method. Furthermore, the amount of mesopore was carefully controlled by adjusting Organic Structure Directing Agent (OSDA) contents in the zeolite framework via partial detemplation. Compared to their parents, the relative crystallinity remains the same for all the desilicated samples. Notably, the occluded OSDA within ZSM-48 may hold another role in desilication, which may affect the density and distribution of the acid site. Low-density polyethylene (LDPE) pyrolysis test exhibits improved catalytic performance for meso-porous samples, showed by the lower observed activation energy (Eobs). It further confirms the benefits of mesopore in enhancing the diffusion of the molecules.

Automated summary

Mesopores were successfully generated through desilication method and the amount of mesopore was controlled by adjusting OSDA contents in the zeolite framework via partial detemplation. The relative crystallinity remained the same for all the desilicated samples compared to their parents. Furthermore, the occluded OSDA within ZSM-48 may have another role in desilication process, affecting the density and distribution of the acid site. The improved catalytic performance of mesoporous samples, as shown by the lower observed activation energy (Eobs) in LDPE pyrolysis test, further confirmed the benefits of mesopores in enhancing molecule diffusion.