TY - JOUR
T1 - Alkylation of poly-substituted aromatics to probe effects of mesopores in hierarchical zeolites with differing frameworks and crystal sizes
AU - Adawi, Hayat I.
AU - Odigie, Florence O.
AU - Sarazen, Michele L.
N1 - Funding Information:
The authors acknowledge support from the High Meadows Environmental Institute at Princeton University, and the use of the Princeton University NMR Facility. The authors also acknowledge the use of Princeton's Imaging and Analysis Center, which is partially supported through the Princeton Center for Complex Materials (PCCM), a National Science Foundation (NSF)-MRSEC program (DMR-2011750). The authors also acknowledge Professor David Hibbitts at the University of Florida for providing access to, and training for, DFT computations through the Computational Catalysis Interface (CCI).51
Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - This study examines how the inherent diffusion constraints of MFI (3D, pore-limiting diameter (PLD) = 0.45 nm), BEA (3D, PLD = 0.60 nm), and MOR (1D, PLD = 0.65 nm) zeolite architectures, at both nanocrystal (nMFI, nBEA, nMOR; dcrystal < 0.5 μm) and microcrystal (μBEA, μMOR; dcrystal > 0.5 μm) scales, impact functions of mesopores in their hierarchical analogs. Reactivities, deactivation rates, and product selectivities were compared among zeolites, as well as to a mesoporous aluminosilicate control (Al-MCM-41; PLD = 6.2 nm), during Friedel-Crafts alkylation of 1,3,5-trimethylbenzene (TMB; dvdW = 0.72 nm) with benzyl alcohol (BA; dvdW = 0.58 nm) to form 1,3,5-trimethyl-2-benzylbenzene (TM2B; dvdW = 0.75 nm). Operation in the neat liquid phase ([TMB]0 : [BA]0 = 35 : 1, 393 K) ensured that the parallel BA self-etherification to yield dibenzyl ether (DBE; dvdW = 0.58 nm) occurred only at the expense of TM2B production when the alkylation reaction was impeded due to hindered access of TMB to confined protons. Investigation of secondary TM2B formation from reaction of DBE with TMB at low [BA]/[DBE] indicates an additional route of selectivity control for hierarchical zeolites that can achieve high BA conversion (XBA > 0.9) with no DBE cofeed. These findings highlight a compounding advantage of increased diffusivity in mesopores that alter rates, extend lifetimes, and subsequently permit secondary reactions that enable significant shifts in product distribution. Fundamental insights into hierarchical zeolite reaction-diffusion-deactivation for alkylation of poly-substituted aromatics, as detailed here, can be applied broadly to reactions of other bulky species, including biomass-derived oxygenates, for more atom-efficient chemical and fuel production.
AB - This study examines how the inherent diffusion constraints of MFI (3D, pore-limiting diameter (PLD) = 0.45 nm), BEA (3D, PLD = 0.60 nm), and MOR (1D, PLD = 0.65 nm) zeolite architectures, at both nanocrystal (nMFI, nBEA, nMOR; dcrystal < 0.5 μm) and microcrystal (μBEA, μMOR; dcrystal > 0.5 μm) scales, impact functions of mesopores in their hierarchical analogs. Reactivities, deactivation rates, and product selectivities were compared among zeolites, as well as to a mesoporous aluminosilicate control (Al-MCM-41; PLD = 6.2 nm), during Friedel-Crafts alkylation of 1,3,5-trimethylbenzene (TMB; dvdW = 0.72 nm) with benzyl alcohol (BA; dvdW = 0.58 nm) to form 1,3,5-trimethyl-2-benzylbenzene (TM2B; dvdW = 0.75 nm). Operation in the neat liquid phase ([TMB]0 : [BA]0 = 35 : 1, 393 K) ensured that the parallel BA self-etherification to yield dibenzyl ether (DBE; dvdW = 0.58 nm) occurred only at the expense of TM2B production when the alkylation reaction was impeded due to hindered access of TMB to confined protons. Investigation of secondary TM2B formation from reaction of DBE with TMB at low [BA]/[DBE] indicates an additional route of selectivity control for hierarchical zeolites that can achieve high BA conversion (XBA > 0.9) with no DBE cofeed. These findings highlight a compounding advantage of increased diffusivity in mesopores that alter rates, extend lifetimes, and subsequently permit secondary reactions that enable significant shifts in product distribution. Fundamental insights into hierarchical zeolite reaction-diffusion-deactivation for alkylation of poly-substituted aromatics, as detailed here, can be applied broadly to reactions of other bulky species, including biomass-derived oxygenates, for more atom-efficient chemical and fuel production.
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U2 - 10.1039/d1me00062d
DO - 10.1039/d1me00062d
M3 - Article
AN - SCOPUS:85117398839
SN - 2058-9689
VL - 6
SP - 903
EP - 917
JO - Molecular Systems Design and Engineering
JF - Molecular Systems Design and Engineering
IS - 11
ER -