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Kennema M, de Castro IBD, Meemken F, Rinaldi R. Liquid-Phase H-Transfer from 2-Propanol to Phenol on Raney Ni: Surface Processes and Inhibition. ACS Catal 2017. [DOI: 10.1021/acscatal.6b03201] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Marco Kennema
- Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany
| | | | - Fabian Meemken
- Department
of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Roberto Rinaldi
- Department
of Chemical Engineering, Imperial College London, SW7 2AZ London, United Kingdom
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2
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Azevedo C, Cenedese P, Dubot P. Two steps bulk-surface functionalization of nanoporous alumina by methyl and vinyl-silane adsorption. Evidence for oxide surface highly reactive sites creation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:1161-1169. [PMID: 21461702 DOI: 10.1007/s10856-011-4286-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 03/08/2011] [Indexed: 05/30/2023]
Abstract
Functionalization of a novel nanoporous monolithic alumina synthesized from amalgam is investigated. The structure is studied by X-ray diffraction, BET, MEB and IR spectroscopy, before and after chemical functionalization by trimethylethoxy silane adsorption and annealing at high temperature. These treatments retain both monolith microstructure and nanostructure while strongly improving material mechanical properties. Allyldimethoxysilane and alcohol adsorption on the annealed samples, proves that highly reactive sites are available for further polymer grafting, as demonstrated by a significant shift of allyldimethoxysilane ν(SiH) to 2,215 cm(-1) and adsorbed acetate formation. Simple quantum computations on model systems support this conclusion. Chemical processes reported in this paper, allow a nanostructured alumina monoliths functionalization to optimize ceramics-polymer bonds, and to tune new hybrid biomaterial properties.
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Affiliation(s)
- Christophe Azevedo
- College d'Odontologie Garanciere Universite Denis Diderot, 5 rue de Garanciere, 75006, Paris, France.
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Pick S. Density-functional study of the methoxy intermediates at Cu(111), Cu(110) and Cu(001) surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:395002. [PMID: 21403215 DOI: 10.1088/0953-8984/22/39/395002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Although the geometry of the methoxy intermediates on copper surfaces has been investigated in a number of experimental and also in several theoretical papers, the situation remains controversial for the (110) and (001) surface orientations. In the present study, we perform density-functional calculations for the Cu(111), (110) and (001) surfaces. The stress is laid upon the models and ideas proposed in the literature. At the (111) face, the fcc three-fold adsorption site is found to be slightly more favourable than the hcp one. At the (110) surface, we predict the methoxy to adsorb close to the short-bridge site in a tilted geometry. Metastable long-bridge positions are less stable by more than 0.3 eV. Since for coverages up to θ = 0.5 the interaction between the methoxy groups is weak, we see no reason for the presence of two different adsorbed methoxy forms unless the copper surface is reconstructed. For the (001) surface we obtain almost the same adsorption energy for the upright adsorbed methoxy in the hollow site, and a tilted methoxy form in a position between the bridge and the hollow site. The calculations agree semiquantitatively with the available experimental data, and admit the presence of two distinct methoxy surface forms.
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Affiliation(s)
- Stěpán Pick
- J Heyrovský Institute of Physical Chemistry of Academy of Sciences of Czech Republic, v.v.i., Dolejškova 3, CZ-182 23 Prague 8, Czech Republic.
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Pang XY, Wang C, Zhou YH, Zhao JM, Wang GC. DFT study of the structure sensitivity for the adsorption of methyl, methoxy, and formate on Ni(111), Ni(100), and Ni(110) surfaces. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.theochem.2010.01.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kubota J, Kusafuka K, Wada A, Domen K, Kano SS. Time-resolved sum-frequency generation spectroscopy of methoxy and deuterated methoxy on Ni(111) using near-infrared laser pulses. J Phys Chem B 2006; 110:10785-91. [PMID: 16771327 DOI: 10.1021/jp060699g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methoxy (CH3O-) and deuterated (d-) methoxy (CD3O-) species on Ni(111) are investigated by sum-frequency generation (SFG) spectroscopy. Methoxy adsorbed on the Ni(111) surface is confirmed by SFG spectroscopy to be oriented normal to the surface. Two resonant peaks produced by methoxy, at 2921 and 2821 cm(-1), are assigned to Fermi resonance between the CH symmetric stretching and overtone modes. Deuterated methoxy exhibits a single strong peak at 2051 cm(-1) assigned to the CD symmetric stretching mode. Investigation of the sub-nanosecond transient behavior of methoxy and d-methoxy species on Ni(111) under short-pulse laser pumping at 1064 nm reveals a clear weakening and recovery of the SFG peaks upon heating. The observed temporal profile is reproduced by simulation assuming that the original methoxy in the ground state is in chemical equilibrium with a new state produced by instantaneous heating. The dependence of the SFG spectra on the initial substrate temperature is also reproduced by the simulation. The simulation suggests a temperature jump of 250 K upon laser pumping, inducing a change in the molecular orientation or adsorption site of methoxy on the Ni(111) surface without decomposition of methoxy to adsorbed CO and hydrogen, which occurs under normal heating at 200 K.
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Affiliation(s)
- Jun Kubota
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuda, Midori-ku, Yokohama 226-8503, Japan.
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Barros RB, Garcia AR, Ilharco LM. Adsorption of [D2]Methanol on Ru(001)O Surfaces: The Influence of Preadsorbed Oxygen on the Methoxide Geometry. Chemphyschem 2005; 6:1299-306. [PMID: 15968697 DOI: 10.1002/cphc.200400546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The influence of oxygen precoverage on the bonding geometry of methoxide on Ru(001) was studied using the isotopically labeled molecule CHD2OH by reflection-absorption infrared spectroscopy (RAIRS). This molecule is an excellent model because the vibrational spectra of CHD2O- may be unambiguously correlated with the adsorption configuration. For Ru(001)--O layers with an effective oxygen coverage (theta0) between 0.25 and 0.6 ML (ML=monolayer), the influence of the oxygen precoverage was shown to vary with the initial methanol exposure. For an extremely low dose of [D2]methanol (0.01 L; L=Langmuir, 1 L=10(-6) torr s), at 90 K, no oxygen-coverage effects were detected on the geometry of [D2]methoxide: it adsorbs in an upright orientation (pseudo-C(3v) local symmetry), just as on clean Ru(001). An increase in the methanol exposure to 0.1 L, at the same temperature, results in the formation of a disordered layer of tilted methoxide: for theta(O)=0.25 ML, C(s)/C1 and intrinsic C1 configurations are present on the surface, whereas for theta(O)> or =0.5 ML, only the former species were identified. The thermal activation of these tilted layers to 105 K results in a lower coverage of upright methoxide for any oxygen precoverage, coadsorbed with decomposition products, as confirmed by the detection of adsorbed formaldehyde and, on the denser oxygen layer (theta(O)=0.6 ML), formate. The influence of the oxygen precoverage becomes determinant when annealing a [D2]methanol multilayer to 105 K: for theta(O)=0.25 ML, the RAIR spectrum correlates with a disordered layer of tilted methoxide and formaldehyde, whereas for theta(O)=0.6 ML upright methoxide, formate, and carbon monoxide were identified. On clean Ru(001), for methanol exposures > or =0.1 L, the C(3v) methoxide configuration was never attained upon thermal activation.
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Affiliation(s)
- Ricardo B Barros
- Centro de Química-Física Molecular, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
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Wang GC, Zhou YH, Morikawa Y, Nakamura J, Cai ZS, Zhao XZ. Kinetic Mechanism of Methanol Decomposition on Ni(111) Surface: A Theoretical Study. J Phys Chem B 2005; 109:12431-42. [PMID: 16852538 DOI: 10.1021/jp0463969] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The decomposition of methanol on the Ni(111) surface has been studied with the pseudopotential method of density functional theory-generalized gradient approximation (DFT-GGA) and with the repeated slab models. The adsorption energies of possible species and the activation energy barriers of the possible elementary reactions involved are obtained in the present work. The major reaction path on Ni surfaces involves the O-H bond breaking in CH(3)OH and the further decomposition of the resulting methoxy species to CO and H via stepwise hydrogen abstractions from CH(3)O. The abstraction of hydrogen from methoxy itself is the rate-limiting step. We also confirm that the C-O and C-H bond-breaking paths, which lead to the formation of surface methyl and hydroxyl and hydroxymethyl and atom hydrogen, respectively, have higher energy barriers. Therefore, the final products are the adsorbed CO and H atom.
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Affiliation(s)
- Gui-Chang Wang
- Department of Chemistry, and the Center of Theoretical Chemistry Study, Nankai University, Tianjin, 300071, P. R. China.
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Wang GC, Zhou YH, Nakamura J. Characterization of methoxy adsorption on some transition metals: A first principles density functional theory study. J Chem Phys 2005; 122:44707. [PMID: 15740283 DOI: 10.1063/1.1839552] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Based on the gradient-density functional theory, calculation results of methoxy adsorption on Au(111), Ag(111), Cu(111), Pt(111), Pd(111), Ni(111), Rh(111), and Fe(100) surfaces are presented, and a consistent picture for some key physical properties determining the reactivity of metals appears. These eight metals belong to two groups: either with filled d electrons (group IB) or with unfilled but more than half filled d electrons (group VIII). The calculated adsorption energies are quite in agreement with the experimental data as well as the previous theoretical calculation results. Importantly, using the analysis of B. Hammer and J. K. Norskov, Nature (London) 376, 232 (1995) and in Chemisorption and Reactivity on Supported Clusters and Thin Films, edited by R. M. Lambert and G. Pacchioni (Kluwer Academic, Dordrecht, 1997), pp. 285-351, the binding energies have selectively been linearly correlated to the d-band center and to the size of the metal d-band orbital overlapping with the adsorbate (coupling matrix element) for these two groups of metals. And by analyzing the nature of the adsorption bonding, the possible reason of this difference is suggested.
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Affiliation(s)
- Gui-Chang Wang
- Department of Chemistry and the Center of Theoretical Chemistry Study, Nankai University, Tianjin 300071, People's Republic of China
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Andersson MP, Uvdal P, MacKerell AD. Fundamental, Binary Combination, and Overtone Modes in Methoxy Adsorbed on Cu(100): Infrared Spectroscopy and Ab Initio Calculations. J Phys Chem B 2002. [DOI: 10.1021/jp012939s] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. P. Andersson
- Chemical Physics, Department of Chemistry, Lund University, PO Box 124, S-221 00 Lund, Sweden
| | - P. Uvdal
- Chemical Physics, Department of Chemistry, Lund University, PO Box 124, S-221 00 Lund, Sweden
| | - A. D. MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, Baltimore, Maryland 21201
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Comparative study of geometry and bonding character for methoxy radical adsorption on noble metals. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0166-1280(99)00286-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mudalige K, Warren S, Trenary M. Vibrational Analysis of a Chemisorbed Polyatomic Molecule: Methoxy on Cu(100). J Phys Chem B 2000. [DOI: 10.1021/jp9933121] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kanchana Mudalige
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
| | - Samantha Warren
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
| | - Michael Trenary
- Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, Illinois 60607-7061
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Ásmundsson R, Uvdal P. Fermi resonance coupling in a surface adsorbate: The C–H stretch in methoxy adsorbed on Cu(100) calculations and experiments. J Chem Phys 2000. [DOI: 10.1063/1.480635] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Weldon MK, Friend CM. Probing Surface Reaction Mechanisms Using Chemical and Vibrational Methods: Alkyl Oxidation and Reactivity of Alcohols on Transitions Metal Surfaces. Chem Rev 1996; 96:1391-1412. [PMID: 11848795 DOI: 10.1021/cr950224d] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marcus K. Weldon
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138Department of Chemistry
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Weldon MK, Uvdal P, Friend CM, Serafin JG. Decoupling of vibrational modes as a structural tool: Coverage‐induced reorientation of methoxide on Mo(110). J Chem Phys 1995. [DOI: 10.1063/1.470594] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Uvdal P, Weldon MK, Friend CM. Adsorbate symmetry and Fermi resonances of methoxide adsorbed on Mo(110) as studied by surface infrared spectroscopy. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:12258-12261. [PMID: 9975384 DOI: 10.1103/physrevb.50.12258] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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