Oxidation of carbon monoxide on poly-oriented and single-crystalline platinum electrodes over a wide range of pH

Gisbert, Rubén; Garcı́a, Gonzalo; Koper, Marc T. M.

doi:10.1016/j.electacta.2010.11.032

Cited by 54 publications

(53 citation statements)

References 35 publications

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“…0.79 V. Again, this feature is absent in the case of Pt nanoparticles. The CO voltammetric profile of the polycrystalline Pt electrode is essentially similar to that previously reported in [9] with similar electrodes and in similar pH conditions. This clear absence of CO oxidation contributions at potentials around 0.8 V and independently of the structure of nanoparticles should suggest that the CO surface mobility from any site toward more active sites on the Pt nanoparticles surfaces should be expected to be much higher than that considered on Pt single crystals.…”

Section: Co Stripping Voltammetry At Shape-controlled Pt Nanoparticlessupporting

confidence: 70%

“…Such conclusion comes from different studies using basal planes and stepped Pt electrodes [6]. In addition, it is also well-known that the CO electro-oxidation reaction on platinum electrodes strongly depends on the surface composition and the electrolyte solution (acidic or alkaline) [7][8][9], as well as the nature of both cations [10] and anions [11]. For Pt(s)-[(n-1)(111)×(110)] electrodes in acid medium, potentiostatic CO stripping experiments at full coverage are characterized by the presence of a single CO oxidation peak [2,6,12].…”

Section: Introductionmentioning

confidence: 99%

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On the behavior of CO oxidation on shape-controlled Pt nanoparticles in alkaline medium

Farias

Vidal‐Iglesias

Solla-Gullón

et al. 2014

Journal of Electroanalytical Chemistry

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In this work, the behavior of the CO electro-oxidation reaction on shape-controlled Pt nanoparticles in alkaline medium was examined in order to understand the effect of the surface structure on this reaction. A series of experiments using Pt nanoparticles of different surface structures/shapes was used and the results obtained were compared with the previous knowledge gained from stepped platinum single crystal electrodes. Independently of the preferential orientation of the nanoparticles, the CO oxidation voltammetry exhibits two main peaks: one at ca. 0.56-059 V and the second one at 0.66 -0.67 V, being the intensity of the peaks dependent on the shape of the nanoparticle. These two peaks have been assigned to the oxidation of CO on the (111) terraces and on the rest of the sites, respectively. The appearance of two differentiated peaks reveals that these (111) terraces and the rest of the sites on the nanoparticle surface behave independently of the presence of the other type of sites, that is, they are not connected. The results are discussed considering the effects of the surface mobility of CO and of the OH adsorption properties on the different sites in the oxidation peaks.

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Section: Co Stripping Voltammetry At Shape-controlled Pt Nanoparticlessupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

On the behavior of CO oxidation on shape-controlled Pt nanoparticles in alkaline medium

Farias

Vidal‐Iglesias

Solla-Gullón

et al. 2014

Journal of Electroanalytical Chemistry

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“…A second difference with the other platinum single crystal electrodes is that the presence of prewaves is only observed for n<12 [42,46], and was previously observed for the Pt(100) electrode [42,44]. The differences may arise from the different coverages obtained in this work.…”

Section: Co Oxidationmentioning

confidence: 49%

On the behavior of the Pt(100) and vicinal surfaces in alkaline media

Arán‐Ais

Figueiredo

Vidal‐Iglesias

et al. 2011

Electrochimica Acta

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Abstract:We address in this paper a voltammetric study of the charge transfer processes characteristic of Pt(100) and vicinal surfaces in alkaline media. The electrochemical behavior of a series of stepped surfaces of the type Pt(S)[n(100)×(111)] has been characterized using cyclic voltammetry at different pHs, charge displacement measurements and FTIR experiments for adsorbed CO. The results from these techniques allow assigning the different peaks appearing in the voltammogram to hydrogen and /or OH adsorption on the different sites characteristic of these surfaces, namely, terrace and step sites. Additionally, the potential of zero total charge (pztc) of the electrodes was also determined. The resulting pztc values shift to more negative values when the step density increases on the surface up to n=5. FTIR spectroscopy experiments have been used to monitor the adsorption of CO on the different surfaces as well as the consequent CO oxidation, accompanying a positive potential sweep. The oxidation of adsorbed CO on (100) terraces is catalyzed by the presence of the (111) steps. The FTIR spectra revealed that CO is mostly bonded in bridge configuration at low potentials interconverting to on-top when the electrode potential is increased.

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“…This reactivity trend Pt(100) < Pt(111) < Pt(110) reported here for the studied RTILs is consistent with some results previously reported in the literature using highly acidic aqueous solutions (the most comparable case to the use of RTILs, since there is a shortage of OH radicals in both media) where the catalytic activity towards the CO oxidation was reported to increase in the same way Pt(100) < Pt(111) < Pt(110). 22 On the contrary, when a much larger amount of OH radicals are available in aqueous solution (pH> 3), there is a change in the catalytic activity towards CO oxidation, being Pt(111) the least active crystallographic plane of platinum at high pH.…”

mentioning

confidence: 99%

Surface-Sensitive Electrooxidation of Carbon Monoxide in Room Temperature Ionic Liquids

et al. 2013

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ABSTRACT:Electrooxidation of CO at the Pt(hkl)-electrolyte interface in two different room temperature ionic liquids (RTILs) is probed to be surface sensitive. Provided data reveal a specific surface structure, (110) sites, which selectively activate CO oxidation in RTILs. This new knowledge is crucial for designing the next generation of Pt nanosized electrocatalysts for the CO oxidation reaction by increasing that type of site on the catalyst surface.A great deal of attention has been devoted to the use of room temperature ionic liquids (RTILs) especially as substitutes for volatile organic solvents used in organic synthesis at industrial scale, 1 but also for the synthesis of inorganic and organometallic compounds.2 Air and moisture-stable RTILs have been regarded as environmentally friendly and alternative solvents thanks to its unique physicochemical features.3-4 For these reasons, RTILs particularly concentrate a great interest in the field of energy storage.5 Carbon monoxide is a common C1 building block in synthesis, extensively used for many different homogenous and heterogeneous catalyzed reactions, in both liquid and gas phase. One of the most relevant reactions conducted via gas phase heterogeneous catalysis is CO hydrogenation following Fischer-Tropsch reaction to form long-chain hydrocarbons. Among the liquid phase catalyzed reactions, electrochemical CO oxidation corresponds to one of the most technologically relevant reactions, 6 since adsorbed CO acts as a poisoning intermediate in many catalytic processes. For this reason, this reaction represents the rate determining step for the total electrochemical combustion of the liquid fuels used in direct fuel cells, such a direct formic acid (DFAFC), methanol (DMFC) or ethanol (DEFC) fuel cells.

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Oxidation of carbon monoxide on poly-oriented and single-crystalline platinum electrodes over a wide range of pH

Cited by 54 publications

References 35 publications

On the behavior of CO oxidation on shape-controlled Pt nanoparticles in alkaline medium

On the behavior of CO oxidation on shape-controlled Pt nanoparticles in alkaline medium

On the behavior of the Pt(100) and vicinal surfaces in alkaline media

Surface-Sensitive Electrooxidation of Carbon Monoxide in Room Temperature Ionic Liquids

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