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Gutierrez-Acebo E, Rey J, Bouchy C, Schuurman Y, Chizallet C. Location of the Active Sites for Ethylcyclohexane Hydroisomerization by Ring Contraction and Expansion in the EUO Zeolitic Framework. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04462] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ester Gutierrez-Acebo
- Rond-point de l’échangeur de Solaize, IFP Energies Nouvelles, BP 3, Solaize 69360, France
| | - Jérôme Rey
- Rond-point de l’échangeur de Solaize, IFP Energies Nouvelles, BP 3, Solaize 69360, France
| | - Christophe Bouchy
- Rond-point de l’échangeur de Solaize, IFP Energies Nouvelles, BP 3, Solaize 69360, France
| | - Yves Schuurman
- CNRS, UMR 5256, IRCELYON, Institut de recherches sur la catalyse et l’environnement de Lyon, Université Lyon 1, 2 Avenue Albert Einstein, F-69626 Villeurbanne, France
| | - Céline Chizallet
- Rond-point de l’échangeur de Solaize, IFP Energies Nouvelles, BP 3, Solaize 69360, France
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2
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Impact of long-range electrostatic and dispersive interactions on theoretical predictions of adsorption and catalysis in zeolites. Catal Today 2018. [DOI: 10.1016/j.cattod.2018.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Sahoo SK, Nair NN. Interfacing the Core-Shell or the Drude Polarizable Force Field With Car-Parrinello Molecular Dynamics for QM/MM Simulations. Front Chem 2018; 6:275. [PMID: 30042939 PMCID: PMC6048201 DOI: 10.3389/fchem.2018.00275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 06/18/2018] [Indexed: 11/13/2022] Open
Abstract
We report a quantum mechanics/polarizable–molecular mechanics (QM/p–MM) potential based molecular dynamics (MD) technique where the core–shell (or the Drude) type polarizable MM force field is interfaced with the plane-wave density functional theory based QM force field which allows Car–Parrinello MD for the QM subsystem. In the QM/p-MM Lagrangian proposed here, the shell (or the Drude) MM variables are treated as extended degrees of freedom along with the Kohn–Sham (KS) orbitals describing the QM wavefunction. The shell and the KS orbital degrees of freedom are then adiabatically decoupled from the nuclear degrees of freedom. In this respect, we also present here the Nosé–Hoover Chain thermostat implementation for the dynamical subsystems. Our approach is then used to investigate the effect of MM polarization on the QM/MM results. Especially, the consequence of MM polarization on reaction free energy barriers, defect formation energy, and structural and dynamical properties are investigated. A low point charge polarizable potential (p–MZHB) for pure siliceous systems is also reported here.
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Affiliation(s)
- Sudhir K Sahoo
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, India
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Mansoor E, Head-Gordon M, Bell AT. Computational Modeling of the Nature and Role of Ga Species for Light Alkane Dehydrogenation Catalyzed by Ga/H-MFI. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04295] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erum Mansoor
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720-1462
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720-1462
| | - Alexis T. Bell
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720-1462
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Tuma C, Sauer J. Quantum chemical ab initio prediction of proton exchange barriers between CH4 and different H-zeolites. J Chem Phys 2015; 143:102810. [PMID: 26374003 DOI: 10.1063/1.4923086] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A hybrid MP2:DFT (second-order Møller-Plesset perturbation theory-density functional theory) method that combines MP2 calculations for cluster models with DFT calculations for the full periodic structure is used to localize minima and transition structures for proton jumps at different Brønsted sites in different frameworks (chabazite, faujasite, ferrierite, and ZSM-5) and at different crystallographic positions of a given framework. The MP2 limit for the periodic structures is obtained by extrapolating the results of a series of cluster models of increasing size. A coupled-cluster (CCSD(T)) correction to MP2 energies is calculated for cluster models consisting of three tetrahedra. For the adsorption energies, this difference is small, between 0.1 and 0.9 kJ/mol, but for the intrinsic proton exchange barriers, this difference makes a significant (10.85 ± 0.25 kJ/mol) and almost constant contribution across different systems. The total values of the adsorption energies vary between 22 and 34 kJ/mol, whereas the total proton exchange energy barriers fall in the narrow range of 152-156 kJ/mol. After adding nuclear motion contributions (harmonic approximation, 298 K), intrinsic enthalpy barriers between 134 and 141 kJ/mol and apparent energy barriers between 105 and 118 kJ/mol are predicted for the different sites examined for the different frameworks. These predictions are consistent with experimental results available for faujasite, ferrierite, and ZSM-5.
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Affiliation(s)
- Christian Tuma
- Institut für Chemie, Humboldt-Universität zu Berlin, Unter den Linden 6, D-10099 Berlin, Germany
| | - Joachim Sauer
- Institut für Chemie, Humboldt-Universität zu Berlin, Unter den Linden 6, D-10099 Berlin, Germany
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Sido A, Walspurger S, Barbiche J, Sommer J. Room-Temperature Alkane Reactivity in Zeolites: An H/D Exchange Study. Chemistry 2010; 16:3215-21. [DOI: 10.1002/chem.200902624] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Zvereva-Loëte N, Ballandras A, Weber G, Rotger M, Boudon V, Simon JM. Experimental IR study andab initiomodelling of ethylene adsorption in a MFI-type host zeolite. Mol Phys 2009. [DOI: 10.1080/00268970903153683] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Stepanov AG, Arzumanov SS, Gabrienko AA, Parmon VN, Ivanova II, Freude D. Significant influence of Zn on activation of the C-H bonds of small alkanes by Brønsted acid sites of zeolite. Chemphyschem 2009; 9:2559-63. [PMID: 18972491 DOI: 10.1002/cphc.200800569] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Herein, we analyze earlier obtained and new data about peculiarities of the H/D hydrogen exchange of small C(1)-n-C(4) alkanes on Zn-modified high-silica zeolites ZSM-5 and BEA in comparison with the exchange for corresponding purely acidic forms of these zeolites. This allows us to identify an evident promoting effect of Zn on the activation of C-H bonds of alkanes by zeolite Brønsted sites. The effect of Zn is demonstrated by observing the regioselectivity of the H/D exchange for propane and n-butane as well as by the increase in the rate and a decrease in the apparent activation energy of the exchange for all C(1)-n-C(4) alkanes upon modification of zeolites with Zn. The influence of Zn on alkane activation has been rationalized by dissociative adsorption of alkanes on Zn oxide species inside zeolite pores, which precedes the interaction of alkane with Brønsted acid sites.
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Affiliation(s)
- Alexander G Stepanov
- Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia.
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Michalik J, Danilczuk M, Turek J, Sadlo J. Stabilisation of reactive intermediates in molecular sieves. RESEARCH ON CHEMICAL INTERMEDIATES 2007. [DOI: 10.1163/156856707782169354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Cai S, Chihaia V, Sohlberg K. Interactions of methane, ethane and pentane with the (110C) surface of γ-alumina. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.05.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Danilczuk M, Pogocki D, Lund A, Michalik J. EPR and DFT study on the stabilization of radiation-generated methyl radicals in dehydrated Na-A zeolite. J Phys Chem B 2007; 110:24492-7. [PMID: 17134207 DOI: 10.1021/jp063506y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy was applied to study paramagnetic species stabilized in Na-A zeolite exposed to gaseous methane and gamma-irradiated at 77 K. Two types of EPR spectra were recorded during thermal annealing of zeolite up to room temperature. Owing to the results for the zeolite exposed to (13)CH(4) the multiplet observed at 110 K was assigned to a (.-)CH(3)...Na(+) complex. After decay of the multiplet, the isotropic quartet of methyl radical was recorded in the temperature range of 170-280 K. On the basis of the EPR parameters it is postulated that (.-)CH(3) radicals in this temperature region are able to freely rotate inside the zeolite cage. The structures of the (.-)CH(3)...Na(+) adsorption complex and respective hyperfine coupling constants were calculated by applying DFT quantum chemical methods. Two different models were applied to represent the zeolite framework: the 6T structure of one six-membered ring and the 3T cluster. The hyperfine coupling constants calculated for the (.-)CH(3)...Na(+) adsorption complex for both applied models show very good agreement with those obtained experimentally.
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Affiliation(s)
- Marek Danilczuk
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
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Walspurger S, Sun Y, Souna Sido AS, Sommer J. Neopentane and Solid Acids: Direct Hydron Exchange before Cracking. J Phys Chem B 2006; 110:18368-73. [PMID: 16970460 DOI: 10.1021/jp0621676] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hydrogen/deuterium exchange reaction of 2,2-dimethylpropane (neopentane) over D(2)O-exchanged zeolites (MOR, FAU, BEA, MFI) using a batch recirculation reactor was studied by means of gas chromatography coupled with mass spectrometer. In the temperature range 473-573 K, H/D exchange proceeds without side reaction such as cracking at short contact times. Indeed the C-H bond has appeared favorably involved in the activation of neopentane compared to the less accessible C-C bond. The transition state allowing hydron exchange is most likely a carbonium species (pentacoordinated carbon) as in the case of the H/D exchange between methane and solid acid. The activation energies of the H/D exchange between neopentane and zeolites are the same for all zeolites indicating a common carbonium ion type transition state. On the basis of previous results in the case of the exchange between methane and liquid superacids, the deuterium exchange rates in neopentane were tentatively related to the acidity of the solids. However the order of activity MOR > MFI > BEA > FAU seems to be related to the size of the pores, which may suggest the involvement of a confinement effect in the zeolites cavities. Moreover we found that H/D exchange takes also place between neopentane and deuterated sulfated zirconia (SZ) emphasizing its strong acidity.
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Affiliation(s)
- Stéphane Walspurger
- Laboratoire de Physicochimie des Hydrocarbures, UMR 7513, Faculté de Chimie, Université Louis Pasteur, 4 rue Blaise Pascal, 67000 Strasbourg, France.
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14
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Zheng X, Blowers P. A computational study of alkane hydrogen-exchange reactions on zeolites. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2005.07.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Tantanak D, Limtrakul J, Gleeson MP. Probing the Structural and Electronic Factors Affecting the Adsorption and Reactivity of Alkenes in Acidic Zeolites Using DFT Calculations and Multivariate Statistical Methods. J Chem Inf Model 2005; 45:1303-12. [PMID: 16180907 DOI: 10.1021/ci0500583] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quantum mechanical (QM) cluster calculations have been performed on a model of ZSM-5 at DFT and MP2 levels. We investigated how the adsorption energies and the energetics of alkoxide intermediate formation of six different alkene substrates, ethene, propene, 1-butene, cis/trans butene, and isobutene, vary in this zeolite model. An analysis of the DFT geometric, electronic, and energetic parameters of the zeolite-substrate complexes, transition states, and alkoxide intermediates is performed using principal components analysis (PCA) and partial least squares (PLS). These deliver an insight into the correlated changes that occur between molecular structure and energy along the reaction coordinate between the physisorbed and chemisorbed species within the zeolite. To the best of our knowledge, this is the first occasion multivariate techniques such as PCA or PLS have been employed to profile the changes in electronics, distances, and angles in QM calculations of catalytic systems such as zeolites. We find the calculated adsorption and the alkoxide intermediate energies correlate strongly with the absolute charge on the substrate and the length of the substrate double bond. The transition states' energies are not affected by the zeolite framework as modeled, which explains why they correlate strongly with the gas-phase substrate protonation energy. Our cluster results show that for ethene, propene, 1-butene, and isobutene, the relative energetics associated with the formation of the alkoxide intermediate in ZSM-5 follow the same trends as calculations where the effects of the framework are included.
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Affiliation(s)
- Duangkamol Tantanak
- Chemistry Department, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
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16
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Lesthaeghe D, Van Speybroeck V, Marin GB, Waroquier M. DFT Investigation of Alkoxide vs Alkylammonium Formation in Amine-Substituted Zeolites. J Phys Chem B 2005; 109:7952-60. [PMID: 16851929 DOI: 10.1021/jp050032e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density functional theory (DFT) cluster calculations were used to describe bifunctional acid-base properties of amine-substituted zeolites containing a Brønsted acid site. Preliminary results (J. Am. Chem. Soc. 2004, 126, 9162) indicated that efficient use of both functional groups might lead to a substantial lowering of activation barriers. In this paper, comparison is made between the alkoxide formation in zeolites containing only oxygen bridges and alkylammonium formation on the bridging NH groups in amine-functionalized zeolites for various guest species, such as methanol, ethene, and chloromethane. The amine functionalization only lowers barriers for SN2 type reactions with otherwise highly strained transition states, as is the case for chloromethane. In these new materials more basic sites are introduced into the zeolite framework, enabling optimal linear SN2 type transition states incorporating various T sites.
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Affiliation(s)
- David Lesthaeghe
- Center for Molecular Modeling, Laboratory of Theoretical Physics, Ghent University, Proeftuinstraat 86, B-9000 Gent, Belgium
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17
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Haouas M, Walspurger S, Taulelle F, Sommer J. The initial stages of solid acid-catalyzed reactions of adsorbed propane. A mechanistic study by in situ MAS NMR. J Am Chem Soc 2004; 126:599-606. [PMID: 14719959 DOI: 10.1021/ja0377549] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In situ solid-state NMR spectroscopy was employed to study the kinetics of hydrogen/deuterium exchange and scrambling as well as (13)C scrambling reactions of labeled propane over Al(2)O(3)-promoted sulfated zirconia (SZA) catalyst under mild conditions (30-102 degrees C). Three competitive pathways of isotope redistribution were observed during the course of the reaction: (1) a regioselective H/D exchange between acidic protons of the solid surface and the deuterons of the methyl group of propane-1,1,1,3,3,3-d(6), monitored by in situ (1)H MAS NMR; (2) an intramolecular H/D scrambling between methyl deuterons and protons of the methylene group, without exchange with the catalyst surface, monitored by in situ (2)H MAS NMR; (3) a intramolecular (13)C scrambling, by skeletal rearrangement process, favored at higher temperatures, monitored by in situ (13)C MAS NMR. The activation energy of (13)C scrambling was estimated to be very close to that of (2)H scrambling, suggesting that these two processes imply a common transition state, responsible for both vicinal hydride migration and protonated cyclopropane formation. All pathways are consistent with a classical carbenium ion-type mechanism.
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Affiliation(s)
- Mohamed Haouas
- RMN et Chimie du Solide, UMR 7140 CNRS, Université Louis Pasteur, 4 rue Blaise Pascal, 67070 Strasbourg Cedex, France
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18
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Ferré N, Assfeld X. A new three-layer hybrid method (LSCF/MM/Madelung) devoted to the study of chemical reactivity in zeolites. Preliminary results. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0166-1280(03)00290-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Vos AM, Schoonheydt RA, De Proft F, Geerlings P. Reactivity Descriptors and Rate Constants for Acid Zeolite Catalyzed Ethylation and Isopropylation of Benzene. J Phys Chem B 2003. [DOI: 10.1021/jp026368v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ann M. Vos
- Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium, and Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
| | - Robert A. Schoonheydt
- Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium, and Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
| | - Frank De Proft
- Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium, and Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
| | - Paul Geerlings
- Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium, and Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
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Rozanska X, van Santen RA, Demuth T, Hutschka F, Hafner J. A Periodic DFT Study of Isobutene Chemisorption in Proton-Exchanged Zeolites: Dependence of Reactivity on the Zeolite Framework Structure. J Phys Chem B 2003. [DOI: 10.1021/jp021646b] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xavier Rozanska
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, NL5600MB Eindhoven, The Netherlands, Totalfinaelf, Raffinerie des Flandres, Département Technique, Secteur Technique no 4, BP 79, F59279 Loon Plage, France, and Institut für Materialphysik, Universität Wien, Sensengasse 8, A1090 Wien, Austria
| | - Rutger A. van Santen
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, NL5600MB Eindhoven, The Netherlands, Totalfinaelf, Raffinerie des Flandres, Département Technique, Secteur Technique no 4, BP 79, F59279 Loon Plage, France, and Institut für Materialphysik, Universität Wien, Sensengasse 8, A1090 Wien, Austria
| | - Thomas Demuth
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, NL5600MB Eindhoven, The Netherlands, Totalfinaelf, Raffinerie des Flandres, Département Technique, Secteur Technique no 4, BP 79, F59279 Loon Plage, France, and Institut für Materialphysik, Universität Wien, Sensengasse 8, A1090 Wien, Austria
| | - François Hutschka
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, NL5600MB Eindhoven, The Netherlands, Totalfinaelf, Raffinerie des Flandres, Département Technique, Secteur Technique no 4, BP 79, F59279 Loon Plage, France, and Institut für Materialphysik, Universität Wien, Sensengasse 8, A1090 Wien, Austria
| | - Juergen Hafner
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, NL5600MB Eindhoven, The Netherlands, Totalfinaelf, Raffinerie des Flandres, Département Technique, Secteur Technique no 4, BP 79, F59279 Loon Plage, France, and Institut für Materialphysik, Universität Wien, Sensengasse 8, A1090 Wien, Austria
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Barich DH, Clawson JS, Stueber D, Strohmeier M, Pugmire RJ, Grant DM. Determination of 13C Chemical Shift Tensors in the Presence of Hydrogen Bonding and 14N Quadrupolar Coupling: p-Aminosalicylic Acid, Isoniazid, and Pyrazinamide. J Phys Chem A 2002. [DOI: 10.1021/jp021604n] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dewey H. Barich
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | | | - Dirk Stueber
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Mark Strohmeier
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Ronald J. Pugmire
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - David M. Grant
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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A Theoretical Study of Hydrodesulfurization and Hydrogenation of Dibenzothiophene Catalyzed by Small Zeolitic Cluster. J Catal 2002. [DOI: 10.1006/jcat.2002.3530] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Goeppert A, Sommer J. H/D exchange, protolysis and oxidation of C3–C5alkanes in HF–SbF5. σ-Basicity vs. reactivity of C–H bonds. NEW J CHEM 2002. [DOI: 10.1039/b201437h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Khaliullin RZ, Bell AT, Kazansky VB. An Experimental and Density Functional Theory Study of the Interactions of CH4 with H−ZSM-5. J Phys Chem A 2001. [DOI: 10.1021/jp012377c] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rustam Z. Khaliullin
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, and Department of Chemical Engineering, University of California, Berkeley, California 94720-1462
| | - Alexis T. Bell
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, and Department of Chemical Engineering, University of California, Berkeley, California 94720-1462
| | - Vladimir B. Kazansky
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt, 47, 117913 Moscow, Russia
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Rozanska X, van Santen RA, Hutschka F, Hafner J. A periodic DFT study of intramolecular isomerization reactions of toluene and xylenes catalyzed by acidic mordenite. J Am Chem Soc 2001; 123:7655-67. [PMID: 11480988 DOI: 10.1021/ja0103795] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A periodic density functional theory (DFT) study of the isomerization reactions of toluene and xylene catalyzed by acidic mordenite is reported. Monomolecular isomerization reactions have been considered and analyzed. The different reaction pathways have been discussed in detail. The use of periodic structure calculations allows consideration and analysis of zeolite electrostatic contributions and steric constraints that occur within zeolite micropores. Major differences in the details of protonation reaction pathways are found when periodic structures are used rather than small cluster models of the Brønsted acidic site. Complex relationships are found between zeolite topology and reaction pathways.
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Affiliation(s)
- X Rozanska
- Schuit Institute of Catalysis, Laboratory of Inorganic Chemistry and Catalysis, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
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Vos AM, Rozanska X, Schoonheydt RA, van Santen RA, Hutschka F, Hafner J. A theoretical study of the alkylation reaction of toluene with methanol catalyzed by acidic mordenite. J Am Chem Soc 2001; 123:2799-809. [PMID: 11456966 DOI: 10.1021/ja001981i] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A theoretical study of the alkylation reaction of toluene with methanol catalyzed by the acidic Mordenite (Si/Al = 23) is reported. Cluster DFT as well as periodical structure DFT calculations have been performed. Full reaction energy diagrams of the elementary reaction steps that lead to the formation of the three xylene isomers are given. The use of periodical structure calculations allows one to account for zeolite framework electrostatic contributions and steric constraints that take place in zeolitic catalysts. Especially the steric constraint energy contribution has a significant effect on the energies and bond formation paths. The activation energy barrier of p-xylene formation is found to be approximately 20 kJ/mol lower than the corresponding values for the formation of its isomers. Computed host-guest binding energies according to the DFT method need a correction due to the absence of the dispersive interaction with the zeolite wall. Apparent activation energies obtained with this correction are in good agreement with experimental data.
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Affiliation(s)
- A M Vos
- Katholieke Universiteit Leuven, Departement Interfasechemie, Kardinaal Mercierlaan 92, B-3001 Heverlee, Belgium
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