Oxide formation as probe to investigate the competition between water and alcohol molecules for OH species adsorbed on platinum

Santiago, Patrícia; Oliveira, Ricardo A. G. de; Roquetto, Júlia Maria; Akiba, Naomi; Gaubeur, Ivanise; Angelucci, Camilo A.; Souza-Garcia, Janaína; Feliú, Juan M.

doi:10.1016/j.electacta.2019.06.037

Cited by 14 publications

(17 citation statements)

References 45 publications

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“…Glycerol oxidation and the formation of a surface oxide layer compete for OH ad , which retards the oxidation of the gold surface in the presence of glycerol. A similar conclusion was reached for several alcohols and platinum by Santiago et al [48], suggesting that this reaction mechanism might be general for all metals and all alcohols, with the exception of methanol at least in the case of Pt [48].…”

Section: Discussionsupporting

confidence: 71%

Reactive and inhibiting species in the electrocatalytic oxidation of glycerol on gold. A study combining in-situ visible reflectance and ATR-SEIRAS

Pérez-Martínez

Balke

Cuesta

2021

Journal of Catalysis

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Section: Discussionsupporting

confidence: 71%

Reactive and inhibiting species in the electrocatalytic oxidation of glycerol on gold. A study combining in-situ visible reflectance and ATR-SEIRAS

Pérez-Martínez

Balke

Cuesta

2021

Journal of Catalysis

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“…The potentiodynamic profiles are characterized by two current peaks at varying magnitude and potentials: at 0.66 and 0.84 V for ethylene glycol, 0.68 and 0.76 V for glycerol, and 0.72 (actually a shoulder with presumably more than one peak, see Figure S2 in the Supporting Information file) and 1.16 V for glucose. At higher potentials, >1.10 V, the oxidation occurs presumably on the oxidized surface. , For the electro-oxidation of formaldehyde, formic acid, methanol, and ethanol, only one current peak and a small shoulder prior to the main peak in some cases were discernible. Although the definition of the current profile in those systems might depend on a number of experimental variables, the use of identical conditions discussed here suggests a, somehow predictable, more complex mechanism for the molecules studied here.…”

Section: Resultsmentioning

confidence: 98%

Electrocatalytic Efficiency of the Oxidation of Ethylene Glycol, Glycerol, and Glucose under Oscillatory Regime

et al. 2021

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There is an increasing interest in the use of small organic molecules in the interconversion between chemical and electrical energies. Among the strategies to improve the processes of yielding electrical energy in fuel cells and the production of cleaner hydrogen in electrochemical reform, there is the use of kinetic instabilities to improve the conversion and selectivity. Herein, we report on the electrocatalytic efficiency of the oxidation of ethylene glycol, glycerol, and glucose, under regular and oscillatory regimes, on polycrystalline platinum, in sulfuric acid aqueous solution, and at 25 °C. Despite the high overpotentials for the electro-oxidation of these molecules, the electrochemical activity along quasi-stationary potentio-/galvanostatic experiments evidenced that, in all cases, relatively lower potential values, and thus higher activity, are reached during oscillations. Noticeably, higher power densities for the electro-oxidation of ethylene glycol and glycerol under the oscillatory regime were found in a hypothetical direct liquid fuel cell. The use of identical experimental conditions of that of our previous study [J. Phys. Chem. C, 2016, 120, 22365] allowed to discuss some universal trends for seven small organic molecules. We compile the results in terms of the peak current, the maximum poisoning rate found along the oscillations, and the oscillation frequency. The three parameters were found to decrease in the order: formaldehyde > formic acid > methanol > ethanol > ethylene glycol > glycerol > glucose. In addition, we discussed the increase of the voltammetric current due to the self-organized poisoning rate and reinforced the trend that high electrocatalytic activity implies high susceptibility to surface poisoning for this set of species. Finally, the analysis done for all species (formic acid, formaldehyde, methanol, ethylene glycol, ethanol, glycerol, and glucose) adds to the available thermodynamic data and is a benchmark against which the activities under the oscillatory regime at 25 °C may be compared or assessed. This point of reference permits to explore further experimental conditions that are relevant for energy-related devices, including the conversion of chemical into electrical energy and the electrochemical reform to produce clean hydrogen in electrolyzers.

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“…A competitive behavior between the two different reactions has already been described in the literature for noble metals. Santiago et al 59 have demonstrated the competition for hydroxyl groups on the electrode surface between alcohol oxidation reactions and platinum oxide formation.…”

Section: Electrochemical Experimentsmentioning

confidence: 99%

Perovskite oxides as electrocatalyst for glycerol oxidation

Santiago

Lima

Bott‐Neto

et al. 2021

Journal of Electroanalytical Chemistry

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Glycerol is a co-product from Biodiesel production with high abundance and low market price. Its transformation into valuable products or as an alternative source of energy has driven the search for selective catalysts. Herein we present the first findings of perovskites as electrocatalysts for glycerol electrooxidation (GEOR). Alternatively to Pt and Pd based catalyst, perovskite oxides (LaNiO3 and LaCoO3) demonstrated high catalytic performance with faradaic currents of ca. 18 mA mg -1 at potentials higher than 1.6 V vs. RHE. Consecutive potential cycles exhibited the LaCoO3 perovskite resistant to poisoning during GEOR. Based on FTIR and online HPLC experiments the GEOR on perovskite oxides yields formic acid and glycolic acid as final products, with no signal of CO2 formation. Our results thus indicate that perovskites can be considered as an alternative for selectively oxidize glycerol, opening the door for a large variety of a new class of catalysts for polyols oxidation with efficiency in terms of current densities and poisoning stability.

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Oxide formation as probe to investigate the competition between water and alcohol molecules for OH species adsorbed on platinum

Abstract: Oxide formation as probe to investigate the competition between water and alcohol molecules for OH species adsorbed on platinum,

Cited by 14 publications

References 45 publications

Reactive and inhibiting species in the electrocatalytic oxidation of glycerol on gold. A study combining in-situ visible reflectance and ATR-SEIRAS

Reactive and inhibiting species in the electrocatalytic oxidation of glycerol on gold. A study combining in-situ visible reflectance and ATR-SEIRAS

Electrocatalytic Efficiency of the Oxidation of Ethylene Glycol, Glycerol, and Glucose under Oscillatory Regime

Perovskite oxides as electrocatalyst for glycerol oxidation

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