Abstract
A hierarchical zeolite Beta has been prepared by a feasible one-pot and one-step method, which is suitable for application in industrial production. The synthesis is a simple hydrothermal process with low-cost raw materials, without adding alcohol or adding seeds, and without aging, recrystallization, and other complex steps. The hierarchical zeolite Beta is a uniform nanocrystal (20–50 nm) aggregation with high external surface area (300 m2/g) and mesoporous volume (0.50 cm3/g), with the mesoporous structure composed of intercrystal and intracrystal pores. As an acid catalyst in benzylation of naphthalene with benzyl chloride, the hierarchical zeolite Beta has shown high activity in the bulky molecule reaction due to its introduction of mesostructure.
Highlights
Zeolite Beta, with its three-dimensional 12-membered ring (12R) microporous structure/network, is one of the three large pore zeolites
As with other zeolites, zeolite Beta has micropores typically smaller than 1 nm, which limits the diffusion of compounds within these pores and the size of molecules that can be catalyzed, for which the mass-transfer problem cannot be ignored when bulky molecules are involved in the reactions catalyzed by microporous zeolites [2]
We report a facile synthesis method, one-pot and one-step, for the preparation of hierarchical zeolite Beta with different size distribution, in which only conventional silica and alumina sources, template and CTBA are used, with only a simple hydrothermal process applied in a sole aqueous system
Summary
Zeolite Beta, with its three-dimensional 12-membered ring (12R) microporous structure/network, is one of the three large pore zeolites. As with other zeolites, zeolite Beta has micropores typically smaller than 1 nm, which limits the diffusion of compounds within these pores and the size of molecules that can be catalyzed, for which the mass-transfer problem cannot be ignored when bulky molecules are involved in the reactions catalyzed by microporous zeolites [2]. Researchers have devoted great efforts to designing microporous-mesoporous or hierarchically structured zeolite to reduce the diffusion path of reactants and products in the zeolite phase to expand its applications [3]. The first is a destructive approach that often results in loss of zeolitic micropores and acid sites. The second strategy is a convenient and versatile approach, in which the inorganic hard templates, e.g., various types of carbon materials such as carbon nanotubes, carbon nanofibers, ordered mesoporous carbons, etc. The second strategy is a convenient and versatile approach, in which the inorganic hard templates, e.g., various types of carbon materials such as carbon nanotubes, carbon nanofibers, ordered mesoporous carbons, etc. were usually used to create mesopores inside the bulk zeolites, though the Materials 2018, 11, 651; doi:10.3390/ma11040651 www.mdpi.com/journal/materials
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
