文摘
Zeolites with high external surface area allow diffusing reactants greater access to catalytically active sites, which has led to interest in the preparation of nanosized zeolites. In this study, a top-down approach has been used for zeolite synthesis by first milling the zeolite to produce nanoparticles. This technique destroys the outer portion of the zeolite framework, causing a significant decrease in its catalytic activity. To remedy this, the damaged part was recrystallized using a dilute silicate solution after bead milling. The combined bead milling and postmilling recrystallization yielded nano ZSM-5 (MFI type zeolite), approximately 60 nm in size, with high crystallinity, and the zeolite powder showed a higher catalytic activity in cumene cracking in comparison with the raw ZSM-5 zeolite. Furthermore, the decrease in crystal size suppresses catalyst deactivation through coke deposition during cumene cracking.