An efficient, rapid, and non-centrifugation synthesis of nanosized zeolites by accelerating the nucleation rate

Access to nanosized zeolites is a topical subject due to the advantageous mass transfer in zeolite catalyzed reactions. Herein we report a low-cost and generalized methodology to decrease zeolite crystal sizes by accelerating the nucleation rate when reducing the solvent amount in the synthesis. As anticipated, nanosized zeolites like MFI (100-200 nm, Si/Al ratios from 100 to infinity in the starting gels) and BEA (50-200 nm, Si/Al ratio of 13) have been successfully synthesized with a H2O/SiO2 ratio of 2.0-3.0. The lower consumption of water as the solvent in the synthesis leads to non-centrifugation for nanosized zeolites, giving higher yields of the zeolite product. Experimental data confirm lower apparent activation energy for nucleation at higher gel concentrations in the synthesis of ZSM-5 zeolites. Catalytic examination of the conversion of methanol to olefins (MTO) demonstrates that the thus-obtained nanosized ZSM-5 zeolite (NS-ZSM-5) exhibits a much longer catalyst lifetime than conventional ZSM-5 (C-ZSM-5) and even nanosized ZSM-5 crystals (NC-ZSM-5) obtained from a hydrothermal route.