Surface electrochemistry of carbon monoxide adsorbed from electrolytic solutions at single crystal surfaces of Pt(111) and Pt(100)

Palaikis, L.; Zurawski, D.; Hourani, Mohammed Khair; Wiȩckowski, Andrzej

doi:10.1016/0039-6028(88)90407-4

Cited by 79 publications

(61 citation statements)

References 52 publications

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“…The potential dependence of the apparent rate constants is essentially independent of the step density: 75 ± 3 mV/dec for Pt(111), 85 ± 3 mV/dec for Pt (15 15 14), 78 ± 4 mV/dec for Pt(554), 97 ± 4 mV/dec for Pt(553), and 81 ± 3 mV/dec for Pt(110). Similar Tafel slopes of 60-80 mV/dec were found in a number of the earlier studies [12,16]. The indifference of the Tafel slope to the surface structure could suggest that CO oxidation follows the same mechanism on all surfaces studied.…”

Section: Co Electrooxidation On Ptsupporting

confidence: 84%

Mechanisms of Carbon Monoxide and Methanol Oxidation at Single-crystal Electrodes

et al. 2007

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The electrochemical oxidation of carbon monoxide and methanol on single-crystal noble metal electrodes has been studied using cyclic voltammetry, chronoamperometry, in situ FTIR spectroscopy, online electrochemical mass spectrometry, and theoretical methods. The oxidation of CO was found to be enhanced by steps and defects. Furthermore, the surface diffusion rate was found to have a significant influence on the kinetics of the oxidation process: for high diffusion rates, such as the oxidation of CO on platinum, the kinetics can be described by a mean field model, while for low diffusion rates, such as CO oxidation on rhodium in sulfuric acid, a nucleationand-growth model was found to be more suitable. Voltammetric and mass spectrometric measurements on the oxidation of methanol on platinum indicate that steps enhance the overall reaction rate. In general, the selectivity towards the direct oxidation pathway through soluble intermediates was found to be higher in the absence of strongly adsorbing anions. In both perchloric and sulfuric acid, this selectivity was also found to increase with increasing step density. In sulfuric acid, Pt(111) shows the highest relative contribution for the direct pathway of all surfaces studied in that electrolyte. Based on these results, a detailed reaction scheme for the electrochemical oxidation of methanol is presented.

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Section: Co Electrooxidation On Ptsupporting

confidence: 84%

Mechanisms of Carbon Monoxide and Methanol Oxidation at Single-crystal Electrodes

et al. 2007

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“…If this deviation is real, one should also observe it in the E p Ϫlog v plots. Only Palaikis et al 5 and Richarz 30 have reported such measurements, unfortunately only at relatively low scan rates, and found slopes of 60-80 mV. Especially the slope of 60 mV is inconsistent with the slopes reported by Love and Lipkowski, and we believe that the explanation given in Sec.…”

Section: E Comparison Of Fast and Slow With Experimentsmentioning

confidence: 61%

“…For the lowest scan rates, both mean field and Dϭ0 predict a slope of ϳ40 mV. Palaikis et al 5 have reported slopes of the E p vs log v plots for the CO oxidation on Pt͑100͒ and Pt͑111͒ of 60Ϯ3 and 80Ϯ5 mV, respectively, Richarz 30 reports a slope of ϳ70 mV for the CO oxidation on polycrystalline Pt. However, these slopes were determined in the relatively narrow scan rate range 5-100 mV s Ϫ1 , exactly the range where the plot is not expected to be linear according to both our simulations.…”

Section: A Cyclic Voltammetry Of Fastmentioning

confidence: 98%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The understanding of the adsorption and electrochemical oxidation of poisonous CO is of paramount importance in the development of improved low temperature fuel cells. Furthermore, CO is a relatively simple molecule which is ideally suited for model studies of molecular adsorption at the metal/electrolyte interface, and its oxidation mechanism is believed to be a simple Langmuir-Hinshelwood surface reaction.…”

Section: Introductionmentioning

confidence: 99%

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Monte Carlo simulations of a simple model for the electrocatalytic CO oxidation on platinum

Koper

Jansen

Santen

et al. 1998

The Journal of Chemical Physics

195

253

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A simple lattice-gas model for the electrocatalytic carbon monoxide oxidation on a platinum electrode is studied by dynamic Monte Carlo simulations. The CO oxidation takes place through a Langmuir-Hinshelwood reaction between adsorbed CO and an adsorbed OH radical resulting from the dissociative adsorption of water. The model enables the investigation of the role of CO surface mobility on the macroscopic electrochemical response such as linear sweep voltammetry and potential step chronoamperometry. Our results show that the mean-field approximation, the traditional but often tacitly made assumption in electrochemistry, breaks down severely in the limit of vanishing CO surface mobility. Comparison of the simulated and experimental voltammetry suggests that on platinum CO oxidation is the intrinsically fastest reaction on the surface and that CO has a high surface mobility. However, under the same conditions, the model predicts some interesting deviations from the potential step current transients derived from the classical nucleation and growth theories. Such deviations have not been reported experimentally. Furthermore, it is shown that our simple model predicts different Tafel slopes at low and high potential, the qualitative features of which are not strongly influenced by the CO mobility. The comparison of our simulation results to the experimental literature is discussed in some detail.

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“…The oxidation kinetics of adsorbed CO on Pt single crystal-electrodes has been extensively studied both in the absence [8][9][10][11][12][13][14][15][16][17][18] and in the presence of dissolved CO in acidic solutions [19][20][21][22]. These studies have revealed that the CO oxidation on Pt(111) and vicinal electrodes takes place according to the mean field Langmuir−Hinselwood (L−H) mechanism [10,11,14,16], in which adsorbed CO reacts with an adsorbed OH species originating from waters' dissociative adsorption.…”

Section: Introductionmentioning

confidence: 99%

CO oxidation on stepped-Pt(111) under electrochemical conditions: insights from theory and experiment

Busó-Rogero

Herrero

Bandlow

et al. 2013

Phys. Chem. Chem. Phys.

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The co-adsorption of CO and OH on two Pt stepped surfaces vicinal to the (111) orientation has been evaluated by means of density functional theory (DFT) calculations. Focusing on Pt(533) and Pt(221), which contain (100) and (111)-steps, respectively, we find that (111)-steps are more reactive towards CO oxidation than surfaces containing (100)-steps. The DFT results are compared with electrochemical experiments on the CO adsorption and oxidation on these vicinal surfaces.

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Surface electrochemistry of carbon monoxide adsorbed from electrolytic solutions at single crystal surfaces of Pt(111) and Pt(100)

Cited by 79 publications

References 52 publications

Mechanisms of Carbon Monoxide and Methanol Oxidation at Single-crystal Electrodes

Mechanisms of Carbon Monoxide and Methanol Oxidation at Single-crystal Electrodes

Monte Carlo simulations of a simple model for the electrocatalytic CO oxidation on platinum

CO oxidation on stepped-Pt(111) under electrochemical conditions: insights from theory and experiment

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