Tandem Aromatization of Oxygenated Furans by Framework Zinc In Zeolites. A Computational Study
Journal Article
·
· Journal of Physical Chemistry. C
- Univ. of Delaware, Newark, DE (United States). Dept. of Chemical and Biomolecular Engineering, and Catalysis Center for Energy Innovation (CCEI)
- Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI)
We have performed electronic structure calculations to characterize the active site of the zeolite CIT-6 (isomorphically substituted Zn-Beta) and to study the Diels–Alder dehydrative aromatization of methyl-5-(methoxymethyl)-furoate (MMFC) and of the dimethyl ester of 2,5-furan-dicarboxylic acid (DMFDC) with ethylene. Three types of active sites have been investigated: a site where the framework charge was balanced by two protons (Z0); a site with an H+ and a Li+ as counter-cations (Z1); and an active site with two Li+ counter-cations (Z2). Using NBO and Bader analysis, we conclude that Zn incorporation into the zeolite framework is not through covalent bonding to framework oxygen atoms but rather is through ionic bonding. Despite the ionic character of the active site and the generally strong Lewis acidic nature of Zn(II) cations, we find no catalysis of the Diels–Alder reaction for the two furans tested. On the other hand, the dehydration of the Diels–Alder cycloadduct can be either Brønsted or Lewis acid catalyzed depending on the active site type. The Z0-type sites are found to be more active than the Z1- and Z2-type sites. Furthermore, the Z0-type sites exhibit both Lewis and Brønsted acid characters with similar catalytic activities. In full agreement with experiment, we find that the conversion of MMFC to (4-methoxymethyl) benzenecarboxylate via Diels–Alder dehydrative aromatization is easier than the conversion of DMFDC to dimethyl terephthalate as the two electron withdrawing groups in DMFDC stabilize the corresponding cycloadduct against dehydration.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Catalysis Center for Energy Innovation (CCEI); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- AC02-05CH11231; SC0001004
- OSTI ID:
- 1482393
- Journal Information:
- Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 40 Vol. 121; ISSN 1932-7447
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Formaldehyde–isobutene Prins condensation over MFI-type zeolites
|
journal | January 2018 |
Similar Records
Catalysis by framework zinc in silica-based molecular sieves
Kinetic regimes in the tandem reactions of H-BEA catalyzed formation of p-xylene from dimethylfuran
Tandem Diels-Alder Reaction of Dimethylfuran and Ethylene and Dehydration to para -Xylene Catalyzed by Zeotypic Lewis Acids
Journal Article
·
Sun Jan 03 19:00:00 EST 2016
· Chemical Science
·
OSTI ID:1387609
Kinetic regimes in the tandem reactions of H-BEA catalyzed formation of p-xylene from dimethylfuran
Journal Article
·
Sat Oct 24 20:00:00 EDT 2015
· Catalysis Science and Technology
·
OSTI ID:1387605
Tandem Diels-Alder Reaction of Dimethylfuran and Ethylene and Dehydration to para -Xylene Catalyzed by Zeotypic Lewis Acids
Journal Article
·
Mon Feb 27 19:00:00 EST 2017
· ChemCatChem
·
OSTI ID:1469842