Competitive adsorption of hydrogen and bromide on Pt(100): Mean-field approximation vs. Monte Carlo simulations

Garcı́a-Aráez, Nuria; Lukkien, Johan J.; Koper, Marc T. M.; Feliu, Juan M.

doi:10.1016/j.jelechem.2005.11.034

Cited by 71 publications

(60 citation statements)

References 28 publications

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“…The presence of sharp peaks in those CVs are associated to the competitive adsorption of hydrogen and anion. At potentials close to the onset of hydrogen evolution, hydrogen is adsorbed on the surface and these species are replaced by adsorbed anions as the potential is scanned in the positive direction giving rise to the appearance of sharp peaks [15]. The absence of significant currents at potentials above 0.5 V indicates that the oxidation of GA for these electrodes and solutions is almost negligible.…”

Section: Resultsmentioning

confidence: 95%

Thermodynamic studies of anion adsorption at the Pt(111) electrode surface from glycolic acid solutions

Arán‐Ais

Herrero

Feliu

2014

J Solid State Electrochem

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Kinetic glycolic acid (GA) oxidation and thermodynamic glycolate adsorption have been studied on Pt single crystal electrodes. The voltammetric profiles of Pt(111), Pt(100) and Pt(110) in 0.1 M GA are shown, and the effect of the inclusion of steps on the Pt(111) surface has been studied by cyclic voltammetry. For Pt(111) electrode, different concentrations and sweep rates have been applied, revealing that both adsorption and oxidation processes take place. By establishing the appropriate conditions, a complete thermodynamic analysis has been performed by using the electrode potential and the charge as independent variables. Total charge density curves, surface pressure at total charge density and at constant electrode potential were determined to calculate the Gibbs excess and the charge number at constant electrode potential for glycolate adsorption on Pt(111). Maximum glycolate coverage on the surface reaches a value of ∼ 6.0 ×10 14 ions/cm 2 . Spectroscopic results show the formation of CO 2 during the oxidation of glycolic acid, indicating that the cleavage of the C-C bond occurs during the oxidation process.

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Section: Resultsmentioning

confidence: 95%

Thermodynamic studies of anion adsorption at the Pt(111) electrode surface from glycolic acid solutions

Arán‐Ais

Herrero

Feliu

2014

J Solid State Electrochem

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“…In particular, detailed thermodynamic analyses have been published about the reversible adsorption of H [4,5,[18][19][20][21][22][23][24][25] and OH [19,26] at different Pt single-crystal surfaces. By analysis of the experimental data [18] and by comparison with Monte Carlo modeling, [27] it has been established that the H upd region is well described by a Frumkin isotherm incorporating repulsive interactions between the adsorbed hydrogens.…”

Section: Introductionmentioning

confidence: 99%

Tuning Adsorption via Strain and Vertical Ligand Effects

Hoster¹,

Alves²,

Koper³

2010

ChemPhysChem

108

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We report on the structure and electrochemical adsorption properties of well-defined pseudomorphic Pt mono- and multilayers on Ru(0001). These act as model surfaces for Pt(111) with slightly decreased affinity to adsorbed hydrogen (H(ad)) and hydroxyl (OH(ad)). In cyclic voltammograms, this is reflected in more negative/positive potential regions for the reversible adsorption of upd-H(ad)/OH(ad), respectively, compared to Pt(111). For upd-H(ad), we show that the corresponding trends can be predicted with high accuracy by density functional theory (DFT). In particular, the upd-H(ad) onset regions can be precisely simulated using the H(ad) adsorption energies from DFT, the layer thickness distribution from STM, and the base voltammogram of Pt(111) as reference.

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“…[10][11][12][13][14][15][16][17][18][19][20][21] Feliu et al, Abruna et al, and others have extensively investigated the influence of halides (I − , Br − , Cl − ) on platinum single crystal electrodes. [22][23][24][25][26][27][28][29][30][31][32][33][34][35] Most of the available surface sensitive techniques were used to elucidate adsorbate coverage and structure. Such techniques, including auger electron spectroscopy (AES), low energy electron diffraction (LEED), second harmonic generation (SHG), surface X-ray scattering (SXS), electrochemical scanning tunneling microscope (ESTM) 31,34 and electrochemical quartz crystal microbalance (EQCM), used to investigate anion adsorption have offered significant insight on the dependence of adsorption process on exposed single crystal orientations.…”

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confidence: 99%

Recovery of Active Surface Sites of Shape-Controlled Platinum Nanoparticles Contaminated with Halide Ions and Its Effect on Surface-Structure

Devivaraprasad¹,

Kar²,

Leuaa³

et al. 2017

J. Electrochem. Soc.

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The interaction of halide ions (I − , Br − , Cl − ) with well-cleaned faceted platinum (nanocube, cuboctahedral) nanoparticles and platinum polycrystalline is investigated in 0.5 M H 2 SO 4 electrolyte. Under electrochemical conditions, the Pt surface gets poisoned with halide ad-atoms and it causes the attenuation of both hydrogen adsorption/desorption in the lower potential region (0.06-0.4 V) and electroxidation of Pt nanoparticles in the higher potential region (0.6-1.2 V). Above certain concentration (5 × 10 −6 M), the strongly adsorbing I − ions mask the H upd features. On the other hand, Br − and Cl − ions alter the peak features in the H upd region, those are characteristic of different Pt surface sites. On excursion to higher potentials (∼>1.2 V), concurrent halogen evolution, Pt oxidation, and oxygen evolution are observed; the increase in peak intensity in the H upd region reflects the reconstruction of the Pt surface. To remove the adsorbed halide ions from the Pt surface, an in-situ potentiostatic method is employed, which involves holding the working electrode at ∼0.03 V in 0.1 M NaOH solution. The cleanliness and retention of surface-structure are confirmed from the voltammograms recorded in the test electrolyte and the recovery of oxygen reduction reaction (ORR) activity after cleaning the Br − ion-contaminated Pt surface supports this conjecture. Anions specifically adsorbed on precious metal surfaces adversely impact several electrochemical reactions including oxidation/ reduction, metal deposition, corrosion and dissolution.1-6 Catalyst poisoning by the adsorbed anions (halides, sulfates and others) is a well-known phenomenon and it decreases the activity of electrocatalysts; for example, in fuel-cell, batteries and electrolyzers. 7,8 Especially platinum, a material for catalyzing a variety of electrochemical reactions, is prone to get poisoned in the presence of adatoms/adsorbates/solution anions under electrochemical conditions. Thus, oxygen reduction reaction (ORR) in fuel cells is affected by the adsorbed species or impurities and it is highly dependent on the cleanliness and surface structure of the catalyst. [9][10][11][12][13] In hydrogen-bromine fuel cells, bromides and bromine species migrate across the membrane and poison the hydrogen-electrode catalyst; moreover, Pt dissolves in Br − ion-containing solutions. 22-35 Most of the available surface sensitive techniques were used to elucidate adsorbate coverage and structure. Such techniques, including auger electron spectroscopy (AES), low energy electron diffraction (LEED), second harmonic generation (SHG), surface X-ray scattering (SXS), electrochemical scanning tunneling microscope (ESTM) 31,34 and electrochemical quartz crystal microbalance (EQCM), used to investigate anion adsorption have offered significant insight on the dependence of adsorption process on exposed single crystal orientations. Thus, AES/LEED studies revealed that Cl − ion adsorption occurs on Pt(100) surface at lower potential than that with Pt(111) surfaces, indi...

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Competitive adsorption of hydrogen and bromide on Pt(100): Mean-field approximation vs. Monte Carlo simulations

Cited by 71 publications

References 28 publications

Thermodynamic studies of anion adsorption at the Pt(111) electrode surface from glycolic acid solutions

Thermodynamic studies of anion adsorption at the Pt(111) electrode surface from glycolic acid solutions

Tuning Adsorption via Strain and Vertical Ligand Effects

Recovery of Active Surface Sites of Shape-Controlled Platinum Nanoparticles Contaminated with Halide Ions and Its Effect on Surface-Structure

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