Infrared study of intermolecular interactions for carbon monoxide chemisorbed on platinum

Hammaker, Robert M.; Francis, S. A.; Eischens, R. P.

doi:10.1016/0371-1951(65)80213-2

Cited by 328 publications

(110 citation statements)

References 8 publications

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“…The effect can be described qualitatively by assuming that in-phase 12 CO-12 CO and 12 CO-13 CO modes contribute intensity to the high frequency band while the less intense out-of-phase 12 CO- 13 CO and in-phase 13 CO- 13 CO modes contribute to the low frequency band. [9][10][11] Thus, the internal C-O frequency shift on Rh͑111͒ at 0.33 ML arises purely from dipole-dipole coupling. In the following we use a small amount of 13 CO as a tracer to investigate the nature of frequency shifts in 12 CO over the entire coverage range up to 0.75 ML.…”

Section: Hreels At 033 ML Co With Variable 12 Coõ 13 Co Compositionmentioning

confidence: 96%

“…Dipole-dipole coupling was first introduced by Hammaker et al 9 in surface vibrational spectroscopy to explain the C-O frequency shifts on silica-supported platinum. Crossley and King 10 confirmed the existence of dipoledipole coupling in vibrational spectra of CO on Pt͑111͒ by using isotopic mixtures of 12 CO and 13 CO. As this type of coupling is a resonance effect between dipoles oscillating at the same frequency, an isolated 13 CO molecule in an environment of 12 CO molecules is not affected by dipole coupling.…”

Section: ͑I͒mentioning

confidence: 99%

“…Crossley and King 10 confirmed the existence of dipoledipole coupling in vibrational spectra of CO on Pt͑111͒ by using isotopic mixtures of 12 CO and 13 CO. As this type of coupling is a resonance effect between dipoles oscillating at the same frequency, an isolated 13 CO molecule in an environment of 12 CO molecules is not affected by dipole coupling. The original description of a vibrating CO adsorbate by Eischens et al 9 has been refined to include the interactions of a dipole and its own image, images of other dipoles, and screening of dipole images by the electronic polarizability of the adsorbate. [15][16][17] The correctness of this description has been confirmed for CO on several metal single crystal surfaces in RAIRS experiments with isotopic mixtures, for a͒ Temporarily on leave from: Departament de Química Física Inorgànica, Universitat Rovira i Virgili, Pl.…”

Section: ͑I͒mentioning

confidence: 99%

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CO/Rh(111): Vibrational frequency shifts and lateral interactions in adsorbate layers

Linke

Curulla

Hopstaken

et al. 2001

The Journal of Chemical Physics

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High resolution electron energy loss spectroscopy ͑HREELS͒, low-energy electron diffraction ͑LEED͒, and thermal desorption spectroscopy ͑TDS͒ were used to study lateral interactions in the adsorbate layer of the CO/Rh͑111͒ system. The vibrational spectra show that CO adsorbs exclusively on top at low coverage. At about half a monolayer a second adsorption site, the threefold hollow site, becomes occupied as well. A steady shift to higher frequencies of the internal C-O vibrations is observed over the whole coverage range. The frequency of the metal CO ͑M-CO͒ vibration in the on-top mode hardly shifts at low coverage. However, upon the emergence of the second adsorption site the M-CO vibrations experience a shift to lower frequencies. The population of the second site is also accompanied by the development of a low temperature shoulder in the TD spectra, indicating an increasingly repulsive interaction in the adsorbed CO layer. Vibrational spectra of isotopic mixtures of 12 CO and 13 CO were used to assess the origin of the observed frequency shifts. They confirm that frequency shifts of the C-O stretching vibration at total CO coverage of 0.33 ML in the (ͱ3ϫͱ3)R30°structure arise purely from dipole-dipole coupling. Dilution of an isotopic species effectively suppresses frequency shifts arising from dipole-dipole coupling. Therefore, experiments with a small amount of 13 CO as a tracer to monitor the frequency shifts in the 12 CO adlayer were carried out over the entire coverage range of 12 CO. The results demonstrate that dipole-dipole coupling causes the frequency shifts at low coverage ͑Ͻ0.5 ML͒, whereas chemical effects set in at higher coverage ͑0.5-0.75 ML͒, connected with the population of the threefold sites. The results illustrate that HREELS in combination with isotopic dilution is a powerful tool in the assessment of lateral interactions between adsorbed molecules.

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Section: Hreels At 033 ML Co With Variable 12 Coõ 13 Co Compositionmentioning

confidence: 96%

Section: ͑I͒mentioning

confidence: 99%

Section: ͑I͒mentioning

confidence: 99%

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CO/Rh(111): Vibrational frequency shifts and lateral interactions in adsorbate layers

Linke

Curulla

Hopstaken

et al. 2001

The Journal of Chemical Physics

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“…A point to note is that the intensities of the V= 16 O and V= 18 O vanadyl vibrations in the bottom spectra in Fig. 3 are not proportional to the concentrations of 16 O and 18 O in the oxide layer since there is an intensity transfer from the low energy band to the high energy band [33][34][35][36]. This can be a significant effect [35] so that the concentration of 16 O in the oxide layer whose data are presented in Fig.…”

Section: (B)mentioning

confidence: 94%

Carbon Dioxide Adsorption on V2O3(0001)

et al. 2017

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oxidation, selective reduction, and dehydrogenation of hydrocarbons and other organic compounds [1,2]. Examples are sulfuric acid production and the oxidation of butane to maleic anhydride [3]. The manifold of catalytic applications has triggered numerous fundamental research studies of vanadium oxides aiming to improve the microscopic understanding of the catalytic processes. A complete overview of the present state of the research cannot be given here; the reader is referred to the literature. Some aspects are summed up in recent review papers [2,[4][5][6][7][8][9]. Catalysts involving vanadium oxides are usually based on V 2 O 5 , which contains vanadium in its highest oxidation state +5, but under reaction conditions the oxidation state may be lower. Therefore the corundum type oxide V 2 O 3 has also been the topic of a number of studies (for an overview, see [2,9]). These studies benefited from the fact that V 2 O 3 layers with (0001) orientation can easily be grown on Au(111), Pd(111), Cu 3 Au(100) and W(110) [2,[9][10][11][12]. Adsorption studies have been performed for methanol [13,14], water [15,16], and O 2 [17]. The surface structure is a critical parameter for the reactivity of a material and therefore the structure of the V 2 O 3 (0001) surface has been investigated thoroughly. Guided mainly by the presence of an intense vanadyl induced feature in vibrational spectra [10,11] is was concluded that the surface should be terminated by a layer of vanadyl groups. This was questioned some years ago by studies which reported that the surface should be terminated by a quasi-hexagonal oxygen layer [18][19][20]. A later I/V-LEED (LEED = low energy electron diffraction; I/V-LEED = LEED intensity analysis) study could show that the initial picture of a vanadyl terminated surface is probably correct [21,22] and therefore we will use the term 'vanadyl terminated' throughout this text. The vanadyl terminated V 2 O 3 (0001) surface can be reduced by electron bombardment such that the oxygen atoms of the vanadyl Abstract The adsorption of carbon dioxide on epitaxially grown V 2 O 3 layers on Au(111) has been studied with thermal desorption and infrared absorption spectroscopy. It is shown that the as-grown grown oxide layer does not react with carbon dioxide; the molecule binds weakly to the surface, stays intact and desorbs below 200 K. If the oxide is weakly reduced such that part or all of the oxygen atoms of the surface vanadyl layer is removed, then a surface carboxylate, i.e. CO − 2 bound to surface vanadium is formed. Part of the CO 2 derived species decompose into O+CO upon annealing, with the oxygen atoms re-oxidizing the reduced oxide surface.

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“…In a subsequent study by Rammaker, Francis, and Eichens, the intermolecular 3 interactions were attributed to dipolar coupling and the system was modeled in 4 that respect.…”

Section: Introductionmentioning

confidence: 99%

Molecular dipole model for the internal optic modes of surface adsorbed molecules: Classical image theory

Nichols

Hexter

1980

The Journal of Chemical Physics

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A molecular dipole model is developed to describe dipolar coupling in surface adsorbed molecules using classical image theory. Only the internal optic modes of the adsorbed molecules are considered. Expanding the dipoles associated with both real and image molecules in terms of the same molecular normal coordinate results in a frequency shift twice that previously expected for dipolar coupling in adsorbed molecules. Application of the model to carbon monoxide adsorbed on platinum indicates that the observed frequency versus coverage behavior can be attributed to dipolar coupling. The irreducible corepresentations of Shubnikov type II, or grey, groups are used to describe the symmetry and spectroscopic activity of the molecule-plus-image system. Infrared activity is associated only with molecular vibrations having nonzero dipole moment derivative components perpendicular to the surface. Raman activity is associated only with those molecular vibrations having nonzero Raman scattering tensor elements αxx, αyy, αzz, or αxy, where z is perpendicular to the surface.

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Infrared study of intermolecular interactions for carbon monoxide chemisorbed on platinum

Cited by 328 publications

References 8 publications

CO/Rh(111): Vibrational frequency shifts and lateral interactions in adsorbate layers

CO/Rh(111): Vibrational frequency shifts and lateral interactions in adsorbate layers

Carbon Dioxide Adsorption on V2O3(0001)

Molecular dipole model for the internal optic modes of surface adsorbed molecules: Classical image theory

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