Computation of the Infrared Spectrum of an Acidic Zeolite Proton Interacting with Acetonitrile

Meijer, EL Eric; Santen, van Ra Rutger; Jansen, Apj Tonek

doi:10.1021/jp951164i

Cited by 32 publications

(38 citation statements)

References 26 publications

(39 reference statements)

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“…To treat this quantum-mechanical problem, we used the ANHARMND package [30]. This package can solve the time-independent Schrödinger equation based on the adiabatic potential energy.…”

Section: Model and Simulation Methodsmentioning

confidence: 99%

The influence of electronic structure on hydrogen absorption in palladium alloys

Kramer

Løvvik

2004

J. Phys.: Condens. Matter

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The influence of the electronic structure and the lattice constant on hydrogen absorption in bulk Pd 3 M 1 (M = Cd, Ag, Au, Pd, Cu, Ni, Pt, Pb, Sn, Fe, Rh, Ru) has been studied by density-functional calculations. We have assumed face-centred cubic structure for all the alloys, and hydrogen has been placed in the octahedral site surrounded by six Pd atoms. We have calculated the absorption energy of hydrogen in the alloys, and found that the influence of the electronic structure is much more important than that of the lattice constant. The results demonstrate that Miedema's empirical rule is also satisfied in this system, i.e., the higher the binding energy of the host alloy, the less stable the hydride. We have also calculated the detailed electronic structures of the alloys and their hydrides. We found that more stable hydrogen absorption is correlated with the hydrogen 1s electrons, palladium s electrons, palladium s-like electrons and the palladium d electrons moving higher in energy towards the Fermi level. The two latter relations have previously been described for bulk systems and surfaces respectively, while this study is apparently the first to point out the correlation between the position of the hydrogen band and the stability of the hydride, i.e., the deeper the hydrogen band, the less stable the hydride.

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“…To treat this quantum-mechanical problem, we used the ANHARMND package [30]. This package can solve the time-independent Schrödinger equation based on the adiabatic potential energy.…”

Section: Model and Simulation Methodsmentioning

confidence: 99%

The influence of electronic structure on hydrogen absorption in palladium alloys

Kramer

Løvvik

2004

J. Phys.: Condens. Matter

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“…The C-O and N-O stretching frequencies were calculated using the ANHARMND program, 28 from a potentialenergy surface consisting of 9-11 points for displacements of ca.Ϯ0.2 Å from the equilibrium bond length. This relatively wide range ensures that we obtain a reasonable description of the first vibrational excited state and possible anharmonic contributions.…”

Section: Methodsmentioning

confidence: 99%

Field-dependent chemisorption of carbon monoxide and nitric oxide on platinum-group (111) surfaces: Quantum chemical calculations compared with infrared spectroscopy at electrochemical and vacuum-based interfaces

Koper

Santen

Wasileski

et al. 2000

The Journal of Chemical Physics

172

133

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Density Functional Theory (DFT) is utilized to compute field-dependent binding energies and intramolecular vibrational frequencies for carbon monoxide and nitric oxide chemisorbed on five hexagonal Pt-group metal surfaces, Pt, Ir, Pd, Rh, and Ru. The results are compared with corresponding binding geometries and vibrational frequencies obtained chiefly from infrared spectroscopy in electrochemical and ultrahigh vacuum environments in order to elucidate the broad-based quantum-chemical factors responsible for the observed metal- and potential-dependent surface bonding in these benchmark diatomic chemisorbate systems. The surfaces are modeled chiefly as 13-atom metal clusters in a variable external field, enabling examination of potential-dependent CO and NO bonding at low coverages in atop and threefold-hollow geometries. The calculated trends in the CO binding-site preferences are in accordance with spectral data: Pt and Rh switch from atop to multifold coordination at negative fields, whereas Ir and Ru exhibit uniformly atop, and Pd hollow-site binding, throughout the experimentally accessible interfacial fields. These trends are analyzed with reference to metal d-band parameters by decomposing the field-dependent DFT binding energies into steric (electrostatic plus Pauli) repulsion, and donation and back-donation orbital components. The increasing tendency towards multifold CO coordination seen at more negative fields is due primarily to enhanced back-donation. The decreasing propensity for atop vs multifold CO binding seen in moving from the lower-left to the upper-right Periodic corner of the Pt-group elements is due to the combined effects of weaker donation, stronger back-donation, and weaker steric repulsion. The uniformly hollow-site binding seen for NO arises from markedly stronger back-donation and weaker donation than for CO. The metal-dependent zero-field DFT vibrational frequencies are in uniformly good agreement with experiment; a semiquantitative concordance is found between the DFT and experimental frequency-field (“Stark-tuning”) slopes. Decomposition of the DFT bond frequencies shows that the redshifts observed upon chemisorption are due to donation as well as back-donation interactions; the metal-dependent trends, however, are due to a combination of several factors. While the observed positive Stark-tuning slopes are due predominantly to field-dependent back-donation, their observed sensitivity to the binding site and metal again reflect the interplay of several interaction components.

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“…In the first method, the m Au-CN and m CN stretching frequencies were calculated from a potential energy surface (PES) consisting of seven or nine points, respectively, within a range of displacements of approximately AE 0.20 A using the AnharmND program [24,25]. A second approach to calculate the vibrational properties of the system, and in particular their dependence on an applied electric field, was by using a cluster model of the surface.…”

Section: Computationalmentioning

confidence: 99%

Cyanide adsorption on gold electrodes: a combined surface enhanced Raman spectroscopy and density functional theory study

Beltramo

Shubina

Mitchell

et al. 2004

Journal of Electroanalytical Chemistry

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Computation of the Infrared Spectrum of an Acidic Zeolite Proton Interacting with Acetonitrile

Cited by 32 publications

References 26 publications

The influence of electronic structure on hydrogen absorption in palladium alloys

The influence of electronic structure on hydrogen absorption in palladium alloys

Field-dependent chemisorption of carbon monoxide and nitric oxide on platinum-group (111) surfaces: Quantum chemical calculations compared with infrared spectroscopy at electrochemical and vacuum-based interfaces

Cyanide adsorption on gold electrodes: a combined surface enhanced Raman spectroscopy and density functional theory study

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