TUD‐1‐Encapsulated HY Zeolite: A New Hierarchical Microporous/Mesoporous Composite with Extraordinary Performance in Benzylation Reactions

Abstract

A new composite material consisting of amorphous TUD‐1 encapsulating crystalline zeolite Y was synthesized. Samples with different HY zeolite loadings (10, 20, 40, and 60 wt %) were prepared, and the resulting solid products were characterized with elemental analysis, XRD, N2 physisorption, 27Al MAS NMR, IR, pyridine adsorption in combination with FTIR, temperature‐programmed desorption of ammonia, HRSEM, and HRTEM. Characterization data confirm the presence of a thin layer of the mesoporous TUD‐1 phase with a thickness of 30–100 nm surrounding the zeolite crystals. The catalytic performance of the composite was studied in the Friedel–Crafts benzylation of benzene with benzyl alcohol at 353 K. The catalytic activity of the HY/TUD‐1 composite was higher than that of HY zeolite, whereas the composite showed a much slower rate of deactivation. The improved performance of the composite is related to beneficial changes in the acidity of the HY crystal through chemical interactions with TUD‐1.

Fluid catalytic cracking: recent developments on the grand old lady of zeolite catalysis

“…Rimer et al 90 influence the crystallization kinetics by applying zeolite growth modifiers (ZGM), organic molecules that impede the growth of specific zeolite crystal planes. The conversion of amorphous cell walls of MCM-41 or SBA-15 type mesoporous materials towards crystalline zeolite structures (such as TUD-C, 91 or zeolite Y encapsulated in TUD-1 92 ) is also considered bottom-up.…”

Bulk and composite catalysts combining BEA topology and mesoporosity for the valorisation of furfural

“…[37][38][39][40][41][42][43] This approach is interesting for preparing catalyst formulations in which the mesoporous phase acts as an inorganic binder of nanocrystallites, provides a somewhat regular network of mesoporous channels for facilitated mass transport of reagents/products and active sites accessibility. This approach has been used to prepare composites of several zeolites (Beta, 38,40,42,[44][45][46][47][48][49][50][51][52][53] Y, [54][55][56] L, [57][58][59] A, 60,61 , ZSM-5 34,35,39,48,[62][63][64][65][66][67][68] , MCM-22 69 ) or zeotypes (SAPO-5, 70,71 silicalite-1 72 ) embedded in mesoporous siliceous phases. The structure of the mesoporous component depends partly on the type and concentration of the templating agent used: e.g.…”

“…Nanocrystalline zeolites have been successfully embedded in the TUD-1 type matrix for different catalytic applications, generally performing better than the corresponding bulk zeolite catalysts: liquid phase alkylation of benzene to ethylbenzene (zeolite Beta), 45 n-hexane cracking (Beta), 38 aldol condensation of benzaldehyde with glycol (ZSM-5) 73 , acetalization of aldehydes (nano-ITQ-2), 74 and benzylation reactions (H-Y). 55 To the best of our knowledge, there are only two studies of zeolite/TUD-1 composite catalysts for reactions related to biomass valorisation; namely, H-Beta/TUD-1 promoted the acid-catalysed dehydration of D-xylose to furfural (Fur) 44 , and conversion of FA (industrially produced via Fur hydrogenation) to LEs. 46 The valorisation of furfural (Fur) is particularly important for the bio-based economy.…”

One-pot synthesis of hierarchically structured ZSM-5 zeolites using single micropore-template

“…Hierarchically structured zeolites (HSZs), which combine crystalline microporous frameworks and auxiliary mesoporous structures, have attracted attention recently [9][10][11][12][13][14]. These materials show superior performance in a wide range of reactions, such as catalytic cracking [15], alkylation of aromatic compounds [16,17], methanol to hydrocarbons [5], and oxidation of organic compounds [18].…”