Surface-science simulation study of the electrochemical charge-transfer reaction (H)ad + (H2O)ad→(H3O+)ad + e−metal on Pt(111) and Cu(110)

Lackey, Damian; Schott, Joachim; Sass, J.K.; Woo, Seong-Ihl; Wagner, Frederick T.

doi:10.1016/0009-2614(91)85123-e

Cited by 38 publications

(33 citation statements)

References 12 publications

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“…For the stepped Pt(533) (not shown), Pt(755), and Pt(977) (not shown) surfaces, the H 2 O stabilization near (100) step sites rapidly disappears when small amounts of deuterium precover the step sites. We believe that the exchange between D and H 2 O takes place through the formation of a hydronium intermediate, which have been observed on Pt(111) 46 and Pt(100) 47 by infrared spectroscopy. As on Pt(111), this desorption temperature increases first when a small amount of D is present.…”

Section: H 2 O Desorption From D Pre-covered Ptmentioning

confidence: 54%

Long-range influence of steps on water adsorption on clean and D-covered Pt surfaces

Dunnen

Niet

Badan

et al. 2015

Phys. Chem. Chem. Phys.

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We have examined water desorption from Pt(111) terraces of varying width and its dependence on precoverage by deuterium (D) with temperature programmed desorption studies. We observe distinct water desorption from (100) steps and (111) terraces, with steps providing adsorption sites with a higher binding energy than terraces. Preadsorption of D at the steps causes annihilation of water stabilization at the steps, while it also causes an initial stabilization of water on the (111) terraces. When the (111) terraces also become precovered with D, this water stabilization trend reverses on all surfaces. Destabilization continues for stepped surfaces containing up to 8-atom wide (111) terraces with a (100) step type and these become hydrophobic, in contrast to surfaces with a (110) step type and with the infinite (111) terrace. Our results illustrate how surface defects and a delicate balance between intermolecular forces and the adsorption energy govern hydrophobic vs. hydrophilic behavior, and that the influence of steps on the adsorption of water on nano-structured platinum surfaces has a very long-ranged character.

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Section: H 2 O Desorption From D Pre-covered Ptmentioning

confidence: 54%

Long-range influence of steps on water adsorption on clean and D-covered Pt surfaces

Dunnen

Niet

Badan

et al. 2015

Phys. Chem. Chem. Phys.

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“…Wagner and Moylan, 70 The authors noted that the smaller than expected work function decrease is due to screening of the positive adsorbate charge by the excess water present. In this work, however, no excess water is included, so the work function calculated is the unscreened value.…”

Section: Resultsmentioning

confidence: 98%

Mechanistic Study of the Electrochemical Oxygen Reduction Reaction on Pt(111) Using Density Functional Theory

Hyman

Medlin

2006

J. Phys. Chem. B

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Density functional theory (DFT) was used to study the electrolyte solution effects on the oxygen reduction reaction (ORR) on Pt(111). To model the acid electrolyte, an H(5)O(2)(+) cluster was used. The vibrational proton oscillation modes for adsorbed H(5)O(2)(+) computed at 1711 and 1010 cm(-1), in addition to OH stretching and H(2)O scissoring modes, agree with experimental vibrational spectra for proton formation on Pt surfaces in ultrahigh vacuum. Using the H(5)O(2)(+) model, protonation of adsorbed species was found to be facile and consistent with the activation barrier of proton transfer in solution. After protonation, OOH dissociates with an activation barrier of 0.22 eV, similar to the barrier for O(2) dissociation. Comparison of the two pathways suggests that O(2) protonation precedes dissociation in the oxygen reduction reaction. Additionally, an OH diffusion step following O protonation inhibits the reaction, which may lead to accumulation of oxygen on the electrode surface.

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“…This is because, although solvent substitution by adsorbates is not usually considered in electrosorption processes [36], the interaction between Hads and the H2Oads network already adsorbed on the electrode may strongly modify the energetic balance on the surface, which in turn may affect the whole adsorption process [31]. In this sense, results from temperature programmed desorption (TPD) experiments on Pt(111) and vicinal surfaces have shown that pre-adsorption of hydrogen, or deuterium, atoms on Pt(111) causes a stabilization of the adsorbed water on the electrode [37][38][39][40][41], together with a small decrease in the H2Oads coverage. Conversely, on {111} vicinal surfaces it weakens the H2O-metal bonding at {110} and {100} steps and, at high coverages, also at {111} terraces [37,[42][43][44].…”

Section: Cvs Inmentioning

confidence: 99%

Thermodynamic properties of hydrogen–water adsorption at terraces and steps of Pt(111) vicinal surface electrodes

Gómez–Marín

Feliu

2016

Surface Science

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Abstract:In this work, the effect of the temperature on the adsorption states of Pt(111) vicinal surface electrodes in perchloric acid is studied through a thermodynamic analysis. The method allows calculating thermodynamic properties of the interface. In this framework, the concept of the generalized isotherm and the statistical thermodynamics description are applied to calculate formal entropies, enthalpies and Gibbs energies, ∆ 0 , of the adsorption processes at two-dimensional terraces and one-dimensional steps. These values are compared with data from literature. Additionally, the effect of the step density on∆ 0 and on the lateral interactions between adsorbed species, ωij, at terraces and steps is also determined. Calculated ∆ 0 , entropies and enthalpies are almost temperature-independent, especially at steps, but they depend on the step orientation. In contrast, ∆ 0 and ωij at terraces depend on the step density, following a linear tendency for terrace lengths larger than 5 atoms. However, while ∆ 0 increases with the step density, ωij decreases. Results were explaining by considering the modification in the energetic surface balance by hydrogen, Hads, and water, H2Oads, co-adsorption on the electrode, which in turn determines the whole adsorption processes on terraces and steps.

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Surface-science simulation study of the electrochemical charge-transfer reaction (H)ad + (H2O)ad→(H3O+)ad + e−metal on Pt(111) and Cu(110)

Cited by 38 publications

References 12 publications

Long-range influence of steps on water adsorption on clean and D-covered Pt surfaces

Long-range influence of steps on water adsorption on clean and D-covered Pt surfaces

Mechanistic Study of the Electrochemical Oxygen Reduction Reaction on Pt(111) Using Density Functional Theory

Thermodynamic properties of hydrogen–water adsorption at terraces and steps of Pt(111) vicinal surface electrodes

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