One pot synthesis of hierarchically macro/microporous ZSM-5 single crystals

Abstract

Hierarchical aluminosilicate-based MFI zeolite single crystals with intracrystalline macropores were fabricated in one pot for the first time. The strategy involved the outward dissolution of the aluminosilicate precursor and simultaneous recrystallization of Si and Al species under the guidance of the organic template tetrapropylammonium bromide. The interesting outward dissolution of the aluminosilicate precursor from core to shell led to the formation of intracrystalline macropores. The Si/Al ratios of these macro/microporous ZSM-5 single crystals could be easily tuned in a wide range by varying the aluminum and alkali contents of the aluminosilicate precursors. The hierarchical ZSM-5 zeolite with highly interconnected macropores exhibited high performance in the 1,3,5-triisopropylbenzene cracking reaction due to the improved intracrystalline diffusion. This study provides a new strategy to fabricate highly efficient zeolites with hierarchical porosity in a simple and cost-effective way.