Electrochemical oxidation of ethanol on Pt(hkl) basal surfaces in NaOH and Na2CO3 media

López-Atalaya, M.; Morallón, Emilia; Cases, F.; Vázquez, José Luís; Pérez, José Miguel Giner

doi:10.1016/0378-7753(94)01950-9

Cited by 28 publications

(33 citation statements)

References 21 publications

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“…In this medium, CO2 formation bands in FTIR were almost negligible and mainly related to pH changes in the thin layer configuration. These results agree with infrared experiments done by Christensen et al with polycrystalline electrodes [36] or older results with single crystal electrodes [37]. However, Lai et al proposed, according with Raman experiments, the adsorption of CO and CHx species on (111) platinum sites during ethanol oxidation [38].…”

Section: Introductionsupporting

confidence: 90%

Oxidation of ethanol on platinum nanoparticles: surface structure and aggregation effects in alkaline medium

Busó-Rogero

Solla-Gullón

Vidal‐Iglesias

et al. 2015

J Solid State Electrochem

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The ethanol oxidation reaction in 0.1 M NaOH on Pt nanoparticles with different shapes and loadings was investigated using electrochemical and spectroscopic techniques. The surface structure effect on this reaction was studied using well-characterized platinum nanoparticles. Regardless of the type of Pt nanoparticles used, results show that acetate is the main product with negligible CO2 formation. From the different samples used, the nanoparticles with a large amount (111) ordered domains have higher peak currents and a higher onset potential, in agreement with previous works with single crystal electrodes.In addition, spherical platinum nanoparticles supported on carbon with different loadings were used for studying possible diffusional problems of ethanol to the catalyst surface.The activity in these samples diminishes with the increase of Pt loading, due to diffusional problems of ethanol throughout the whole Pt nanoparticle layer, being the internal part of the catalyst layer inactive for the oxidation. To avoid this problem and prepare more dispersed nanoparticle catalyst layers, deposits were dried while the carbon support was rotated to favor the dispersion of the layer around the support. The improvement in the electrocatalytic activity for ethanol oxidation confirms the better performance of this procedure for depositing and drying.

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Section: Introductionsupporting

confidence: 90%

Oxidation of ethanol on platinum nanoparticles: surface structure and aggregation effects in alkaline medium

Busó-Rogero

Solla-Gullón

Vidal‐Iglesias

et al. 2015

J Solid State Electrochem

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“…This is especially true when small organic molecules, such as CH 3 OH 28−30 and C 2 H 5 OH, 31 are used as fuels since these molecules do not undergo complete oxidation to CO 2 . Particularly, in case of methanol oxidation on Pt in alkaline media, HCOO − has been indicated as one of the main oxidation products (eq 7) at high potentials (>0.6 V vs RHE).…”

Section: Journal Of the American Chemical Societymentioning

confidence: 99%

An Electrochemical Quartz Crystal Microbalance Study of a Prospective Alkaline Anion Exchange Membrane Material for Fuel Cells: Anion Exchange Dynamics and Membrane Swelling

et al. 2014

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A strategy has been devised to study the incorporation and exchange of anions in a candidate alkaline anion exchange membrane (AAEM) material for alkaline fuel cells using the electrochemical quartz crystal microbalance (EQCM) technique. It involves the electro-oxidation of methanol (CH3OH) under alkaline conditions to generate carbonate (CO3(2-)) and formate (HCOO(-)) ions at the electrode of a quartz crystal resonator coated with an AAEM film, while simultaneously monitoring changes in the frequency (Δf) and the motional resistance (ΔR(m)) of the resonator. A decrease in Δf, indicating an apparent mass increase in the film, and a decrease in ΔR(m), signifying a deswelling of the film, were observed during methanol oxidation. A series of additional QCM experiments, in which the effects of CH3OH, CO3(2-), and HCOO(-) were individually examined by changing the solution concentration of these species, confirmed the changes to be due to the incorporation of electrogenerated CO3(2-)/HCOO(-) into the film. Furthermore, the AAEM films were found to have finite anion uptake, validating the expected tolerance of the material to salt precipitation in the AAEM. The EQCM results obtained indicated that HCOO(-) and CO3(2-), in particular, interact strongly with the AAEM film and readily displace OH(-) from the film. Notwithstanding, the anion exchange between CO3(2-)/HCOO(-) and OH(-) was found to be reversible. It is also inferred that the film exhibits increased swelling in the OH(-) form versus the CO3(2-)/HCOO(-) form. Acoustic impedance analysis of the AAEM-film coated quartz resonators immersed in water showed that the hydrated AAEM material exhibits significant viscoelastic effects due to solvent plasticization.

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“…In-situ infrared spectroscopic studies have shown the that adsorbed CO is a primary poisoning species and acetate is a primary product for ethanol oxidation by platinum in alkaline media [81]. In addition, it has been found that ethanol undergoes a more complete oxidation to CO 2 in alkaline media than in acid media by the same platinum anode [8].…”

Section: Alkaline Mediamentioning

confidence: 99%

“…The kinetics of both cathodic oxygen reduction and anodic oxidation of organic molecules are much more facile in alkaline media in comparison to acid media which presents a key advantage [8,57,63,74,80,81]. In alkaline environment, studies into suitable electrocatalysts for ethanol oxidation are spotty but in general, platinum and palladium based catalysts have been the primary focus.…”

Section: Alkaline Mediamentioning

confidence: 99%

Nanostructured electrocatalyst for fuel cells : silica templated synthesis of Pt/C composites.

Stechel¹,

Switzer²,

Fujimoto³

et al. 2007

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Platinum-based electrocatalysts are currently required for state-of-the-art fuel cells and represent a significant portion of the overall fuel cell cost. If fuel cell technology is to become competitive with other energy conversion technologies, improve the utilization of precious metal catalysts is essential. A primary focus of this work is on creating enhanced nanostructured materials which improve precious-metal utilization. The goal is to engineer superior electrocatalytic materials through the synthesis, development and investigation of novel templated open frame structures synthesized in an aerosol-based approach.Bulk templating methods for both Pt/C and Pt-Ru composites are evaluated in this study and are found to be limited due to the fact that the nanostructure is not maintained throughout the entire sample. Therefore, an accurate examination of structural effects was previously impossible. An aerosol-based templating method of synthesizing nanostructured Pt-Ru electrocatalysts has been developed wherein the effects of structure can be related to electrocatalytic performance. The aerosol-based templating method developed in this work is extremely versatile as it can be conveniently modified to synthesize alternative materials for other systems. The synthesis method was able to be extended to nanostructured Pt-Sn for ethanol oxidation in alkaline media. Nanostructured Pt-Sn electrocatalysts were evaluated in a unique approach tailored to electrocatalytic studies in alkaline media. At low temperatures, nanostructured Pt-Sn electrocatalysts were found to have significantly higher ethanol oxidation activity than a comparable nanostructured Pt catalyst. At higher temperatures, the oxygen-containing species contribution likely provided by Sn is insignificant due to a more oxidized Pt surface. The importance of the surface coverage of oxygen-containing species in the reaction mechanism is established in these studies. The investigations in this work present original studies of anion exchange ionomers as entrapment materials for rotating disc electrode (RDE) studies in alkaline media. Their significance is linked to the development of membrane electrode assemblies (MEAs) with the same ionomer for a KOH-free alkaline fuel cell (AFC). 4 5

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Electrochemical oxidation of ethanol on Pt(hkl) basal surfaces in NaOH and Na2CO3 media

Cited by 28 publications

References 21 publications

Oxidation of ethanol on platinum nanoparticles: surface structure and aggregation effects in alkaline medium

Oxidation of ethanol on platinum nanoparticles: surface structure and aggregation effects in alkaline medium

An Electrochemical Quartz Crystal Microbalance Study of a Prospective Alkaline Anion Exchange Membrane Material for Fuel Cells: Anion Exchange Dynamics and Membrane Swelling

Nanostructured electrocatalyst for fuel cells : silica templated synthesis of Pt/C composites.

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