Dissociative adsorption of ethanol on Pt (h, k, l) basal surfaces

Cases, F.; López-Atalaya, M.; Vźquez, J.L.; Aldaz, A.; Clavilier, J.

doi:10.1016/0022-0728(90)85156-y

Cited by 44 publications

(26 citation statements)

References 17 publications

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“…It is therefore attributed to the incomplete oxidation of the adsorbates, where the reaction products still remain on the surface (no other volatile species were detected). The existence of a pre-peak closely resembles previous findings for Pt(111) [5,12,31]. The two oxidation regions and two peaks in the low potential region suggest that different decomposition products are formed upon dissociative ethanol adsorption in the two potential regions.…”

Section: Oxidation and Reduction Of Ethanol Adsorbate On Pt/vulcansupporting

confidence: 75%

“…Based on the significant structural effects reported in previous studies [12] and the pronounced effects of experimental parameters, such as electrode roughness/catalyst loading or electrolyte flow on the methanol oxidation reaction pathway [21], the reaction kinetics and pathways in a direct ethanol fuel cell may deviate considerably from the results obtained with the model electrodes discussed above. Therefore, this work involves a detailed study of the reaction mechanism of the ethanol oxidation reaction (EOR) on a more realistic system, on carbon supported Pt catalyst electrodes, under continuous flow conditions.…”

Section: Introductionmentioning

confidence: 78%

See 1 more Smart Citation

Ethanol and Acetaldehyde Adsorption on a Carbon‐Supported Pt Catalyst: A Comparative DEMS Study

Wang

Jusys

Behm³

2004

Fuel Cells

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The adsorption of ethanol and acetaldehyde on carbon Vulcan supported Pt fuel cell catalyst and the electrochemical desorption of the adsorption products were studied, using electrochemical measurements and differential electrochemical mass spectrosmetry (DEMS), under continuous flow conditions. Faradaic current adsorption transients at different constant adsorption potentials, which also include CO adsorption for comparison, show pronounced effects of the adsorption potential and the nature of the reactant molecule. Acetaldehyde adsorption is much faster than ethanol adsorption at all potentials. Pronounced Had induced blocking effects for ethanol adsorption are observed at very cathodic adsorption potentials, < 0.16 V, while for acetaldehyde adsorption this effect is much less significant. Comparison of the adsorption charge for CO adsorption with the H‐upd charge allows differentiation between H‐displacement and double‐layer charging effects. Continuous bulk oxidation is observed for both reactants at potentials > 0.31 V; for acetaldehyde adsorption, increasing bulk reduction is found at low potentials. Based on the electron yield per CO2 molecule formed and on the similarity with the CO stripping characteristics the dominant stable adsorbate is CO, coadsorbed with smaller amounts of (partly oxidized) hydrocarbon decomposition fragments, which are also oxidized at higher potentials (> 0.85 V) and which can be reductively desorbed as methane or, to a very small extent, as ethane. The presence of small amounts of adsorbed C2 species and the oxidative dissociation of these species in the main CO oxidation potential range is clearly demonstrated by increased methane desorption after a potential shift to 0.85 V. The data demonstrate that the Pt/Vulcan catalyst is very reactive for C‐C bond breaking upon adsorption of these reactants.

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Section: Oxidation and Reduction Of Ethanol Adsorbate On Pt/vulcansupporting

confidence: 75%

Section: Introductionmentioning

confidence: 78%

Ethanol and Acetaldehyde Adsorption on a Carbon‐Supported Pt Catalyst: A Comparative DEMS Study

Wang

Jusys

Behm³

2004

Fuel Cells

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“…The electrochemical response for ethanol adspecies has been reported in the past three decades by many authors [20][21][22][37][38][39][40][41][42]. However, the identification of other adsorbates than (CO) ad was first conducted with the help of DEMS by Willsau and Heitbaum [37], finding a dissociative adsorption process.…”

Section: Discussionmentioning

confidence: 97%

Heterogeneously assisted oxidation of adsorbates from carbonmonoxide, methanol and ethanol by hydrogen peroxide solutions on platinum electrodes in sulphuric acid

et al. 2006

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The influence of hydrogen peroxide on the adsorption and oxidation of carbon monoxide, methanol and ethanol adlayers on porous Pt electrodes were studied in 2 M sulphuric acid solution by means of cyclic voltammetry and differential electrochemical mass spectrometry (DEMS). The oxidation of adsorbed species is observed at electrode potentials far less negative than those required for electrochemical adsorbate oxidation. The oxidation by H 2 O 2 is dependent on its concentration in solution, as well as on the adsorbates and their coverages. In all cases the isolated adlayers are oxidised by dissolved H 2 O 2 . However, the presence of H 2 O 2 during adsorption partially inhibits adlayer formation from CH 3 OH and C 2 H 5 OH, but avoids almost completely the adsorption of carbon monoxide. The removal of the residues from the surface by dissolved hydrogen peroxide probably occurs through O ad species formed during the heterogeneous decomposition reaction of H 2 O 2 on Pt.

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“…On Pt (111) electrodes, only acetic acid is formed without poison formation. However, on Pt (100) and Pt (110) electrodes, C-C bond scission is observed and CO is formed, blocking the surface for further reaction at low potentials [3,4]. On the other hand, the oxidation in alkaline solutions leads to the almost exclusive production of acetate and negligible amounts of CO and CO2 (carbonate at higher pH values) [5].…”

mentioning

confidence: 99%

“…Step (3) and step (4) show the C-C bond scission from acetaldehyde and ethanol respectively, needed to achieve CO2 formation. However, previous to the complete oxidation, CO is formed and poisons the catalyst surface.…”

Section: Introductionmentioning

confidence: 99%

Adatom modified shape-controlled platinum nanoparticles towards ethanol oxidation

Busó-Rogero

Solla-Gullón

Vidal‐Iglesias

et al. 2016

Electrochimica Acta

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Different adatom modified shape-controlled Pt nanoparticles have been prepared and their electrocatalytic properties have been evaluated toward ethanol electrooxidation.Based on previous findings with Pt model surfaces, Sn, Rh, Ru and Pb adatoms have been selected as promising surface modifiers. The different adatoms have been gradually incorporated on the surface of the preferentially oriented (100) and (111) Pt nanoparticles under electrochemical conditions. The results obtained in 0.5 M H2SO4 indicated that, among the selected adatoms, Sn-modified nanoparticles displayed not only a significant shift to negative values on the onset potential of the ethanol oxidation, but also an important decrease on the hysteresis between the positive and negative sweeps.Interestingly, in chronoamperometic measurements at 0.6 V, the oxidation enhancement factors have been found to be dependent on the surface structure of the Pt nanoparticles.On the other hand, Ru and Pb-modified Pt nanoparticles only presented a rather small oxidation enhancement, whereas the activity of the Rh-modified Pt nanoparticles clearly diminished. In alkaline solutions, the oxidation mechanism changes, and the adsorption of Rh, Sn and Pb on the platinum surfaces just displays small catalytic effect at lower This is a previous version of the article published in Electrochimica Acta. 2016Acta. , 196: 270-279. doi:10.1016Acta. /j.electacta.2016 2 coverage for the potential onset in the voltammetric experiments. Ru adsorption does not present any positive effect over the reaction.Keywords: Ethanol oxidation, electrocatalysis, Pt-based electrodes, tin, rhodium, ruthenium, lead, shape-controlled nanoparticles. IntroductionNowadays, the studies about new energy sources are gaining momentum due to the depletion of fossil fuels. One of these alternative energy sources is the development of fuel cells, which can obtain energy simply from the reaction between a fuel and an oxidant species (usually oxygen). Fundamental research in fuel cells is usually centered in the material used for manufacturing the catalyst and its electrocatalytic response to the desired reaction on the cathode or on the anode [1]. As a catalyst, platinum is a good choice due to its well-known catalytic properties. Different chemicals have been selected as possible candidates for using as a fuel in the anode, from the most typical hydrogen to some small organic molecules such as formic acid, methanol or ethanol. Among these organic molecules, ethanol is one of the most studied fuels [2], because it presents some advantages as the easiness for obtaining it from biomass in addition to its low toxicity or its high energy density for the complete oxidation to CO2, where 12 electrons are exchanged according with the reaction:Nevertheless, this reaction is not as simple as appears in the general equation presented above, because parallel reactions can occur, decreasing the efficiency of the complete oxidation, the desired route. When using platinum as catalyst, this reaction has shown ...

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Dissociative adsorption of ethanol on Pt (h, k, l) basal surfaces

Cited by 44 publications

References 17 publications

Ethanol and Acetaldehyde Adsorption on a Carbon‐Supported Pt Catalyst: A Comparative DEMS Study

Ethanol and Acetaldehyde Adsorption on a Carbon‐Supported Pt Catalyst: A Comparative DEMS Study

Heterogeneously assisted oxidation of adsorbates from carbonmonoxide, methanol and ethanol by hydrogen peroxide solutions on platinum electrodes in sulphuric acid

Adatom modified shape-controlled platinum nanoparticles towards ethanol oxidation

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