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Raybaud P, Costa D, Corral Valero M, Arrouvel C, Digne M, Sautet P, Toulhoat H. First principles surface thermodynamics of industrial supported catalysts in working conditions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:064235. [PMID: 21693896 DOI: 10.1088/0953-8984/20/6/064235] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ever stronger environmental concerns prompt the research in the area of heterogeneous catalysis to play an ever more crucial role to produce ever cleaner fuel from the refining of petroleum effluents. The catalytic active phase is often used in a dispersed state over a porous oxide material. This paper is a review of recent progress brought by periodic density functional theory (DFT) calculations in the area of two relevant industrial supported catalysts. We focus on two important supports used in the refining industry: anatase-TiO(2) and γ-alumina. According to the various reaction conditions, the presence of H(2)O, H(2) and H(2)S may change the surface states of the support. In particular, it is crucial to know and control the hydroxylation state depending on temperature and partial pressure of reactants (H(2)O, H(2), H(2)S). The support effects on the catalytic active phases are presented for MoS(2) particles, used in hydrodesulfurization catalysis, and for Pd particles, used in hydrogenation catalysis. It is shown how the wetting property and equilibrium morphology of the active phase depend on the support. A discussion on the impact for catalytic activities is provided.
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Benco L, Bucko T, Hafner J, Toulhoat H. Periodic DFT calculations of the stability of Al/Si substitutions and extraframework Zn2+ cations in mordenite and reaction pathway for the dissociation of H2 and CH4. J Phys Chem B 2007; 109:20361-9. [PMID: 16853635 DOI: 10.1021/jp0530597] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The local stability of Al atoms replacing Si in the zeolite framework is compared for all inequivalent tetrahedral (T) sites in mordenite. For Al/Si substitutions in two T sites the stable location of the compensating extraframework Zn(2+) cation forming a Lewis acid site is determined. In the most stable Zn-MOR structures Zn(2+) is located in a small ring (5MR, 6MR) containing two Al/Si substitutions. In less stable structures the Al atoms are placed at larger distances from each other and Zn(2+) interacts with only one Al site. The simulated adsorption of H(2) and CH(4) shows that adsorption strength decreases with increasing stability of the Zn(2+) Lewis site. A higher adsorption strength is observed for Zn(2+) deposited in the 5MR than for the 6MR. The reactivity of a series of stable Zn(2+) Lewis sites is tested via the dissociative adsorption of H(2) and CH(4). The heterolytic dissociation of the adsorbed molecule on the extraframework Zn(2+) cation produces a proton and an anion. The anion binds to Zn(2+) and proton goes to the zeolite framework, restoring a Brønsted acid site. Because bonding of the anion to Zn(2+) is almost energetically equivalent for Zn(2+) in any of the extraframework positions the dissociation is governed by stabilizing bonding of the proton to the framework. Those structures which can exothermically accommodate the proton represent reaction pathways. Due to the repulsion between the proton and Zn(2+) the most favorable proton-accepting O sites are not those of the ring where Zn(2+) is deposited, but O sites close to the ring. Large differences are observed for neighboring positions in a- and b-directions and those oriented along the c-vector. Finally, among the stable Zn(2+) Lewis sites not all represent reaction pathways for dehydrogenation. For all of them the dissociation of H(2) is an exothermic process. In structures exhibiting the highest reactivity the Al/Si substitutions are placed at a large distance and the Zn(2+) cation interacts with O-atoms next to Al in the T4 site of the 5MR. This Lewis site is strong enough to break the C-H bond in the CH(4) molecule.
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Digne M, Raybaud P, Sautet P, Guillaume D, Toulhoat H. Quantum chemical and vibrational investigation of sodium exchanged γ-alumina surfaces. Phys Chem Chem Phys 2007; 9:2577-82. [PMID: 17508090 DOI: 10.1039/b700541e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The sodium cation is well known as an efficient poison of gamma-alumina surface acidity. This poisoning effect has been revealed both by characterization methods and catalytic tests. In this work, we propose an accurate model of sodium exchanged gamma-alumina surfaces. On realistic models of hydroxylated gamma-alumina surfaces, the location of sodium cation is determined by the use of density functional theory (DFT) methods. For the (100) and (110) surfaces of gamma-alumina, the sodium cation is found in a solvated state within an inner solvation sphere complex. Its coordination sphere is constituted by O-mu(2), O-mu(3) and HO-mu(1) surface groups. The stretching frequency of these HO-mu(1) groups is shifted, leading to the appearance of a new band predicted and observed at about 3754 cm(-1) on the IR spectrum.
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Jacquin Y, Toulhoat H, Quignard A, Le Page JF. Développements récents dans le domaine de l'hydrotraitement des fractions lourdes. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1983022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Gualda G, Toulhoat H. Etude de la desactivation des catalyseurs d'hydrotraitement par cokage. Synthèse bibliographique. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1988036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Tanoubi I, Martinerie P, Bourseau P, Muratet G, Toulhoat H. Simulation de la désactivation d'un catalyseur d'hydrodémétallisation à géométrie ouverte. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1991018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bourseau P, Muratet G, Saillour C, Toulhoat H. Evolution au cours du temps d'un grain de catalyseur d'hydrodémétallisation : module et simulation numérique de résultats expérimentaux. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1985037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Toulhoat H, Clemendot S. Évaluation précise des acidités au niveau DFT : application aux catalyseurs solides superacides. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1996004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kessas R, Toulhoat H. L'hydrodésazotation des distillats issus de la conversion des hydrocarbures lourds. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1986030] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Toulhoat H. Potentiel et limites d'utilisation, aux températures élevées, des lubrifiants liquides dans les moteurs. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1989024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Digne M, Raybaud P, Sautet P, Rebours B, Toulhoat H. Comment on “Examination of Spinel and Nonspinel Structural Models for γ-Al2O3by DFT and Rietveld Refinement Simulations”. J Phys Chem B 2006; 110:20719-20; author reply 20724-6. [PMID: 17034264 DOI: 10.1021/jp061466s] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Benco L, Bucko T, Hafner J, Toulhoat H. A Density Functional Theory Study of Molecular and Dissociative Adsorption of H2 on Active Sites in Mordenite. J Phys Chem B 2005; 109:22491-501. [PMID: 16853930 DOI: 10.1021/jp0533729] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adsorption and chemisorption of H2 in mordenite is studied using ab initio density functional theory (DFT) calculations. The geometries of the adsorption complex, the adsorption energies, stretching frequencies, and the capacity to dissociate the adsorbed molecule are compared for different active sites. The active centers include a Brønsted acid site, a three-coordinated surface Al site, and Lewis sites formed by extraframework cations: Na+, Cu+, Ag+, Zn2+, Cu2+, Ga3+, and Al3+. Adsorption properties of cations are compared for a location of the cation in the five-membered ring. This location differs from the location in the six-membered ring observed for hydrated cations. The five-membered ring, however, represents a stable location of the bare cation. In this position any cation exhibits higher reactivity compared with the location in the six-membered ring and is well accessible by molecules adsorbed in the main channel of the zeolite. Calculated adsorption energies range from 4 to 87 kJ/mol, depending on electronegativity and ionic radius of the cation and the stability of the cation-zeolite complex. The largest adsorption energy is observed for Cu+ and the lowest for Al3+ integrated into the interstitial site of the zeolite framework. A linear dependence is observed between the stretching frequency and the bond length of the adsorbed H2 molecule. The capacity of the metal-exchanged zeolite to dissociate the H2 molecule does not correlate with the adsorption energy. Dissociation is not possible on single Cu+ cation. The best performance is observed for the Ga3+, Zn2+, and Al3+ extraframework cations, in good agreement with experimental data.
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Toulhoat H, Hudebine D, Raybaud P, Guillaume D, Kressmann S. THERMIDOR: A new model for combined simulation of operations and optimization of catalysts in residues hydroprocessing units. Catal Today 2005. [DOI: 10.1016/j.cattod.2005.08.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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de Bruin TJM, Lorant F, Toulhoat H, Goddard WA. Reaction Kinetics of a Selected Number of Elementary Processes Involved in the Thermal Decomposition of 9-Methylphenanthrene Using Density Functional Theory. J Phys Chem A 2004. [DOI: 10.1021/jp0372486] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Benco L, Bucko T, Hafner J, Toulhoat H. Ab Initio Simulation of Lewis Sites in Mordenite and Comparative Study of the Strength of Active Sites via CO Adsorption. J Phys Chem B 2004. [DOI: 10.1021/jp048056t] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Arrouvel C, Digne M, Breysse M, Toulhoat H, Raybaud P. Effects of morphology on surface hydroxyl concentration: a DFT comparison of anatase–TiO2 and γ-alumina catalytic supports. J Catal 2004. [DOI: 10.1016/j.jcat.2003.10.016] [Citation(s) in RCA: 232] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Mittendorfer F, Thomazeau C, Raybaud P, Toulhoat H. Adsorption of Unsaturated Hydrocarbons on Pd(111) and Pt(111): A DFT Study. J Phys Chem B 2003. [DOI: 10.1021/jp035660f] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Benco L, Hafner J, Hutschka F, Toulhoat H. Physisorption and Chemisorption of Some n-Hydrocarbons at the Brønsted Acid Site in Zeolites 12-Membered Ring Main Channels: Ab Initio Study of the Gmelinite Structure. J Phys Chem B 2003. [DOI: 10.1021/jp027625z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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de Bruin TJM, Magna L, Raybaud P, Toulhoat H. Hemilabile Ligand Induced Selectivity: a DFT Study on Ethylene Trimerization Catalyzed by Titanium Complexes. Organometallics 2003. [DOI: 10.1021/om030255w] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Benazzi E, Leite L, Marchal-George N, Toulhoat H, Raybaud P. New insights into parameters controlling the selectivity in hydrocracking reactions. J Catal 2003. [DOI: 10.1016/s0021-9517(03)00041-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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47
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Toulhoat H, Raybaud P. Kinetic interpretation of catalytic activity patterns based on theoretical chemical descriptors. J Catal 2003. [DOI: 10.1016/s0021-9517(02)00118-5] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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48
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Rose J, De Bruin TJM, Chauveteau G, Tabary R, Hazemann JL, Proux O, Omari A, Toulhoat H, Bottero JY. Aqueous Zirconium Complexes for Gelling Polymers. A Combined X-ray Absorption Spectroscopy and Quantum Mechanical Study. J Phys Chem B 2003. [DOI: 10.1021/jp027114c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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Anisimov MA, Yudin IK, Nikitin V, Nikolaenko G, Chernoutsan A, Toulhoat H, Frot D, Briolant Y. Asphaltene Aggregation in Hydrocarbon Solutions Studied by Photon Correlation Spectroscopy. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100023a040] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Houssenbay S, Kasztelan S, Toulhoat H, Bonnelle JP, Grimblot J. Nature of the different nickel species in sulfided bulk and alumina-supported nickel-molybdenum hydrotreating catalysts. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100357a030] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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