Oxygen reduction at platinum electrodes: The interplay between surface and surroundings properties

Gómez–Marín, Ana M.; Feliu, Juan M.

doi:10.1016/j.coelec.2018.03.018

Cited by 29 publications

(15 citation statements)

References 60 publications

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“…2(a), as discussed above, changes in the structure of the interfacial water close to the surface could account for the slight decrease in j lim . 54 A gradual diminution in j lim during the ORR, without an increase in H 2 O 2 formation, has also been found in clean surfaces as the pH of the solution is increased, and it has been attributed to a kinetic effect on the reduction of OOH * . 52,55 It is expected that, since the reduction of this species would require the addition of a proton, its kinetics would be affected by the structure of water close to the surface and more difficult to achieve in neutral pH values, relative to acid solutions.…”

Section: B Oxygen Reduction On Te Modified Pt(111) Surfaces In Non-adsorbing Electrolytesmentioning

confidence: 96%

Structure effects on electrocatalysts. Oxygen reduction on Te-modified Pt(111) surfaces: Site-blocking vs electronic effects

Gómez–Marín¹,

Briega-Martos

Feliú

2020

The Journal of Chemical Physics

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In this work, the oxygen reduction reaction (ORR) on tellurium-modified Pt(111) surfaces has been studied. Adsorption of Te adatoms on Pt(111) progressively shifts toward less positive values of both the ORR reaction onset and the half-wave potential in 0.1M HClO 4 for 0 < θ Te < 0.25. However, at θ Te > 0.25, the ORR activity increases relative to the one at θ Te < 0.25, but remains lower than that on clean Pt(111). Results were analyzed in light of simulations of kinetic currents as a function of θ Te , calculated by employing a simple mean field model including both site blocking and electronic effects. Inside this framework, experimental data are best explained by considering that oxygenated Te species inhibit the ORR by either negatively modifying adsorption energies of reaction intermediates or combined site-blocking and electronic effects. A redox ORR catalysis due to redox properties of Te adatoms is discarded. Contrarily, in 0.05M H 2 SO 4 , a positive catalytic effect has been found, interpreted in terms of a competitive adsorption-desorption mechanism involving the replacement of adsorbed sulfate by Te adatoms. On the other hand, despite the strong site-blocking effect on H ads and OH ads adsorption by Te adatoms, it appears that the reduced Te-Pt(111) adlayer does not inhibit the reaction, suggesting different active sites for H ads and OH ads adsorption and for the rate-determining step of the ORR mechanism.

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Section: B Oxygen Reduction On Te Modified Pt(111) Surfaces In Non-adsorbing Electrolytesmentioning

confidence: 96%

Structure effects on electrocatalysts. Oxygen reduction on Te-modified Pt(111) surfaces: Site-blocking vs electronic effects

Gómez–Marín¹,

Briega-Martos

Feliú

2020

The Journal of Chemical Physics

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“…In the last five years, more than 1000 review articles have been published on various electrodes, in different systems, and under different conditions. Much attention continues to be paid to the Pt electrode in relation to the above reactions [2][3][4][5][6][7][8]. This is also important in view of the development of highly sensitive oxygen sensors.…”

Section: Introductionmentioning

confidence: 99%

“…Whether the features of electrochemical oxidation of rCO 2 into carbon dioxide saturated aqueous H 2 CO 3 solution without electrolyte additives can be detected? (2).…”

Section: Introductionmentioning

confidence: 99%

Dynamics of Oxidation of Reduced Forms of CO2 under Electrochemical and Open-Сircuit Conditions on Polycrystalline Pt in H2CO3

Smolin

Михайлов

Gadzaov

et al. 2021

Metals

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The problem of identifying correlations between catalytic and electrocatalytic processes is one of the fundamental problems of catalysis among “simple” organic substances, and the oxidation of CO and rCO2 is of great interest, since CO and CO2 are considered in pairs both during catalytic and electrocatalytic transformations. In the case of electrocatalysis, this analysis is important in the study of fuel cells. In this paper, we studied the correlation between the oxidation of reduced forms of CO2 (rCO2) under potentiodynamic-galvanoctatic electrochemical and open-circuit conditions of measurements on polycrystalline (pc)Pt in H2CO3. Periodic oscillations are revealed at the oxidation of Had and rCO2 on (pc)Pt. Quantum chemical calculations were carried out on the Pt13 cluster in order to identify the mechanisms of the rCO2 oxidation reaction. The correspondence in the energy parameters of the oxidation process of rCO2 under open-circuit conditions and electrochemical conditions is shown. The preliminary analysis of the system using density functional (DFT) calculations is carried out and the most stable systems that are based on Pt13 are found, namely rOH-Pt13-(CO)n, rOH-Pt13-(COH) and rOH-Pt13-(rCOOH). OH• species was chosen as the most likely candidate for the role of the oxidant for rCO2. Preliminary calculations for the expected reactions were carried out, and the optimal PES is revealed.

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“…[1][2][3][4][5][6] For example, for the direct methanol/ethanol fuel cells, the anodic potential is operated at above 0.8 V (vs. reversible hydrogen electrode), which could lead to changes of the surface species. The electrochemistry of Pt materials is critical in both electrooxidation of fuels and electroreduction of dioxygen.…”

Section: Introductionmentioning

confidence: 99%

“…The electrochemistry of Pt materials is critical in both electrooxidation of fuels and electroreduction of dioxygen. [1][2][3][4][5][6] For example, for the direct methanol/ethanol fuel cells, the anodic potential is operated at above 0.8 V (vs. reversible hydrogen electrode), which could lead to changes of the surface species. [3,6] For the cathodic reaction of oxygen reduction reaction, Pt materials could be undermined by the irreversible surface change and Pt dissolution with intensive cycling.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Insights into Cyclic Voltammograms on Pt(111): Kinetics Simulations

et al. 2019

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A detailed understanding of the electrochemistry of platinum electrodes is of great importance for the electrochemical oxidation of fuels and electrochemical reduction of dioxygen in fuel cells. The Pt(111) facet is the most representative model mimicking Pt nanoparticles and polycrystals for fundamental studies. Herein, we propose a site-specific model accompanied with the typical elementary steps of the electrochemistry of Pt (111) in non-adsorbing electrolyte within the potential range between 0.05 and 1.15 V versus reversible hydrogen electrode. Simulations were conducted at different scanning rates based on the kinetics models. We reproduce all the anodic and cathodic peaks observed in the reported experimental curves. These results demonstrate the underlying mechanisms of the peak formation in different potential regions.probably affects the surface reactions. In the current simplified model, mass transfer was not considered. However, the trend of peak shifting is the same with experimental data, which is sufficient and reasonable to do qualitative analyses. Compared Figure 2. Comparison of the simulated (red solid) with experimental (blue dashed) CV curves (a, c, e, g). The experimental data were extracted from the reference. [29] The coverage of the surface species corresponding to the simulated CV curves at different scan rates: (b) 0.005 V s À 1 , (d) 0.05 V s À 1 , (f) 0.5 V s À 1 , (h) 5 V s À 1 . Each curve in a color contains the forward and backward scan labeled with arrow. In the case of the curve without arrow, the forward and backward scans overlap.

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Oxygen reduction at platinum electrodes: The interplay between surface and surroundings properties

Cited by 29 publications

References 60 publications

Structure effects on electrocatalysts. Oxygen reduction on Te-modified Pt(111) surfaces: Site-blocking vs electronic effects

Structure effects on electrocatalysts. Oxygen reduction on Te-modified Pt(111) surfaces: Site-blocking vs electronic effects

Dynamics of Oxidation of Reduced Forms of CO2 under Electrochemical and Open-Сircuit Conditions on Polycrystalline Pt in H2CO3

Mechanistic Insights into Cyclic Voltammograms on Pt(111): Kinetics Simulations

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