Micron‐Sized Zeolite Beta Single Crystals Featuring Intracrystal Interconnected Ordered Macro‐Meso‐Microporosity Displaying Superior Catalytic Performance

Abstract

Zeolite Beta single crystals with intracrystalline hierarchical porosity at macro-, meso-, and micro-length scales can effectively overcome the diffusion limitations in the conversion of bulkym olecules.H owever,t he construction of large zeolite Beta single crystals with such porosity is ac hallenge.W er eport herein the synthesis of hierarchically ordered macro-mesoporous single-crystalline zeoliteB eta (OMMS-Beta) with ar are micron-scale crystal size by an in situ bottom-up confined zeolite crystallization strategy.The fully interconnected intracrystalline macro-meso-microporous hierarchy and the micron-sized single-crystalline nature of OMMS-Beta lead to improved accessibility to active sites and outstanding (hydro)thermal stability.Higher catalytic performances in gas-phase and liquid-phase acid-catalyzed reactions involving bulkymolecules are obtained compared to commercial Beta and nanosized Beta zeolites.T he strategy has been extended to the synthesis of other zeolitic materials,i ncluding ZSM-5, TS-1, and SAPO-34.

Structured Binder-Free Al-β Zeolite for Acid-Catalyzed Dehydration

“…The 29 Si spectra were referenced to 4,4-dimethyl-4-silapentane sulfonate sodium. 27 Al MAS NMR spectra were acquired at 130.2 MHz using a 4 mm MAS NMR probe with 14 kHz spinning speed. The 27 Al spectra were referenced to 1% Al(NO 3 ) 3 aqueous solutions.…”

Improvement of adsorption and catalytic properties of zeolites by precisely controlling their particle morphology

“…The synthesized highly ordered macro-mesomicroporous Beta is highly active for gas-phase cracking of 1,3,5-triisopropylbenzene (1,3,5-TIPB) and liquid-phase benzylation of benzene with benzyl alcohols. 85…”

Hierarchy: enhancing performances beyond limits

“…The first to be mentioned is the work on micron-sized zeolite single crystals featuring hierarchical intracrystal interconnected ordered macro-meso-microporosity made by Su's group, the pioneers of the field, which is considered as one of the most important milestones of the field [ 3 , 10 , 11 ]. It is well known that as a size- and shape-selective catalyst, zeolites are widely used in petroleum and fine chemicals processing.…”

“…Such unique hierarchically porous architecture within one single zeolite crystal with high thermal and hydrothermal stability and excellent mechanic strength can maximize the rate of intracrystalline diffusion of reactants and products, the accessibility to active sites and thus the catalytic efficiency of each of the zeolite single crystals. This leads to a significant reduction in coking and deactivation rate, outstanding catalytic activity and selectivity, and highly improved catalyst lifetime in methanol-to-olefins [ 10 ], bulky molecules cracking [ 10 , 11 ] and Friedel-Crafts alkylation of benzene with benzyl alcohol [ 11 ] reactions. Their in situ bottom-up confined crystallization strategy with regard to the hierarchically porous zeolite single crystal is highly universal and has been extended to the successful synthesis of other zeolitic materials, including ZSM-5, Beta, TS-1 and SAPO-34.…”

“…(h–j) SEM images of an individual crystal from three directions. Adapted with permission from refs [ 10 ] and [ 11 ]. Copyright 2020 Elsevier.…”