The adsorption of water on Pt(111) studied by irreflection and UV-photoemission spectroscopy

Langenbach, E.; Spitzer, A.; Lüth, H.

doi:10.1016/0039-6028(84)90174-2

Cited by 95 publications

(48 citation statements)

References 13 publications

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“…2). These findings on the water-water interactions are in accordance with [59][60][61] are included as well. The adsorption distances have been defined as difference between the average height of the O atoms and the average height of the metal atoms of the uppermost layer.…”

Section: Resultssupporting

confidence: 90%

Dispersive interactions in water bilayers at metallic surfaces: A comparison of the PBE and RPBE functional including semiempirical dispersion corrections

2012

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The accuracy and reliability of the density functional theory (DFT)-D approach to account for dispersion effects in first-principles studies of water-metal interfaces has been addressed by studying several water-metal systems. In addition to performing periodic DFT calculations for semi-infinite substrates using the popular PBE and RPBE functionals, the water dimer and water-metal atom systems have also been treated by coupled-cluster calculations. We show that indeed semiempirical dispersion correction schemes can be used to yield thermodynamically stable water bilayers at surfaces. However, the actual density functional needs to be chosen carefully. Whereas the dispersion-corrected RPBE functional yields a good description of both the water-water and the water-metal interaction, the dispersion-corrected PBE functional overestimates the energies of both systems. In contrast thereto, the adsorption distances predicted by the PBE functional is hardly changed due to the additional dispersion interaction, explaining the good performance of previous DFT-PBE studies of water-metal systems.

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Section: Resultssupporting

confidence: 90%

Dispersive interactions in water bilayers at metallic surfaces: A comparison of the PBE and RPBE functional including semiempirical dispersion corrections

2012

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“…11,27,43,44,49 As a result, compared to others, we underestimate the charge transfer and, thus, get a less negative polar and a larger Pt(111) . Most experimental values reported for the PZC of Pt are of the order 0.4 V versus SHE, 31,[54][55][56] which would correspond to a Pt(111) of about 4.8 eV and a water-induced WF change of approximately −1 eV. Obviously, among our systems, only a few of the neutral water films, treated at the PBE level, match these experimental values.…”

Section: A Sensitivity Of the Pzc To Water Structure And XC Functionalmentioning

confidence: 47%

Standard hydrogen electrode and potential of zero charge in density functional calculations

et al. 2011

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Methods to explicitly account for half-cell electrode potentials have recently appeared within the framework of density functional theory. The potential of the electrode relative to the standard hydrogen electrode is typically determined by subtracting the experimental value of the absolute standard hydrogen electrode potential (ASHEP) from the calculated work function. Although conceptually correct, this procedure introduces two sources of errors: (i) the experimental estimate of the ASHEP varies from 4.28 to 4.85 V and, as has been previously shown and is reconfirmed here, (ii) the calculated work function strongly depends on the structure of the water film covering the metal surface. In this paper, we first identify the most accurate experimental reference for the ASHEP by revisiting up-to-date literature, and validate the choice of electron reference level in single-electrode density functional setups. By analyzing a dozen different water structures, built up from water hexamers, in their uncharged [potential of zero charge (PZC)] states on Pt(111), we then determine three different criteria (no net dipole, no charge transfer, and high water flexibility) that a water structure should possess in order for its computed ASHEP to closely match the experimental benchmark. We capture and quantify these three effects by calculating trends in the ASHEP and PZC on eight close-packed transition metals, considering the four most simple and representative water models. Finally, it is also demonstrated how the work function changes with exchange-correlation functional.

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“…The adsorption of H 2 O on metal surfaces was intensively studied in the past [1]. Different investigations of the system H 2 O͞Pt(111) [2][3][4][5][6] show that water adsorbs via island formation [3,5]. The desorption peak temperatures in thermal desorption spectroscopy (TDS) experiments were determined to be 165 and 175 K for the multilayer and the so-called bilayer, respectively [3,4].…”

Section: Markus Morgenstern Thomas Michely and George Comsamentioning

confidence: 99%

Anisotropy in the Adsorption ofH2O at Low Coordination Sites on Pt(111)

1996

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The H 2 O adsorption on Pt(111) at 140 K is investigated by temperature-variable scanning tunneling microscopy. H 2 O adsorbs preferentially at the upper side of step edges. At these low coordination sites the adsorbates are bound stable as quasi-one-dimensional chains up to 160 K. In contrast, the desorption from the two-dimensional H 2 O islands on the terrace has already started at 145 K. The occupancy of the sites at the upper side of step edges is different at the two types of dense packed steps. This adsorption anisotropy is correlated with the different dipole moment of the two types of steps. [S0031-9007 (96)00492-9] PACS numbers: 68.45.Da, 81.10.Aj, 82.65.My The adsorption of H 2 O on metal surfaces was intensively studied in the past [1]. Different investigations of the system H 2 O͞Pt(111) [2][3][4][5][6] show that water adsorbs via island formation [3,5]. The desorption peak temperatures in thermal desorption spectroscopy (TDS) experiments were determined to be 165 and 175 K for the multilayer and the so-called bilayer, respectively [3,4]. First principle calculations of the interaction of single H 2 O molecules with a Pt 10 cluster have shown that the binding between Pt and H 2 O is mainly caused by the mixing of unoccupied Pt 5d states with the occupied lone pair orbitals of the H 2 O molecule. This results in an energy gain of about 0.5 eV. The adsorption site was found to be on top. The reason is that the Pt charge density on top is lower, which reduces the repulsive part of the interaction [7].In this work we present the first scanning tunneling microscopy (STM) study of water adsorption on a metal surface, which shows that H 2 O adsorbs preferentially at the low coordination sites at the upper side of step edges. This appears to be the adsorption site of highest thermal stability. Surprisingly, the H 2 O occupancy of these sites is different for the two types of dense packed steps.The experiments were performed in an UHV-STM apparatus described elsewhere [8]. The background pressure was below 1 3 10 210 mbar. The sample was prepared by repeated cycles of Ar 1 bombardment, oxygen exposure, and subsequent flashing to 1000 ± C. This procedure results in a clean, well-ordered surface as checked by low energy electron diffraction Auger electron spectroscopy and the STM. Water of milli-Q quality with an electrical resistivity of 10 7 Vcm was used for the exposure. Just before water exposure the sample was flashed to 500 ± C to desorb all adsorbates from the surface. The water adsorption has been performed by filling the chamber with a H 2 O pressure of 5 3 10 29 1.1 3 10 28 mbar and keeping the sample temperature at 140 K. The gas inlet was routinely checked by a mass spectrometer with automatic background subtraction. The only peak not related to H 2 O, which has an intensity of more than 0.1% of the H 2 O peak, was M 28 with an intensity corresponding to somewhat less than 1% of H 2 O. We assume that this is due to residual N 2 solved in the water reservoir. However, N 2 does not adsorb on Pt(111) d...

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The adsorption of water on Pt(111) studied by irreflection and UV-photoemission spectroscopy

Cited by 95 publications

References 13 publications

Dispersive interactions in water bilayers at metallic surfaces: A comparison of the PBE and RPBE functional including semiempirical dispersion corrections

Dispersive interactions in water bilayers at metallic surfaces: A comparison of the PBE and RPBE functional including semiempirical dispersion corrections

Standard hydrogen electrode and potential of zero charge in density functional calculations

Anisotropy in the Adsorption ofH2O at Low Coordination Sites on Pt(111)

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