Chemisorption of methanol on different platinum electrodes (smooth and rough polycrystalline, monocrystalline, and preferentially oriented), as studied by EMIRS

Beden, B.; Hahn, F.; Lamy, C.; Léger, Jean‐Michel; Tacconi, Norma R. de; Lezna, Reynaldo O.; Arvía, Alejandro Jorge

doi:10.1016/0022-0728(89)85008-9

Cited by 44 publications

(13 citation statements)

References 19 publications

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“…The voltammogram obtained (Fig. 5) is very similar to that observed for platinum electrodes at the same conditions [24,25]. However, the current peak and the ratio between the current for the forward scan (I f ) and the backward scan (I b ), which are related to carbon dioxide and carbon monoxide produced by methanol oxidation, respectively [26], diminished with the number of cycles.…”

Section: Resultssupporting

confidence: 70%

3D Electrodes from aluminium foams prepared by replication process

et al. 2009

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Aluminium foams with pores displaying both regular size and distribution have been prepared by replication methods. Their volumetric density and electrical conductivity were 0.65 g cm -3 and 2.44 MS m -1 , respectively. This method represents a simple way to produce 3D metal macroporous electrodes. In addition, the aluminium foam has been employed as support to produce 3D platinum electrodes (Pt/Al foam) by electrodeposition. The conditions for platinum electrodeposition have been established, and the electrodes were characterized by scanning electron microscopy and cyclic voltammetry. The electrocatalytic behaviour of the Pt/Al foam electrodes to methanol oxidation has been tested in 1 M CH 3 OH ? 0.5 M H 2 SO 4 solutions.

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Section: Resultssupporting

confidence: 70%

3D Electrodes from aluminium foams prepared by replication process

et al. 2009

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“…Within the last decade, there has been an avalanche of new techniques to prepare catalysts for methanol electro-oxidation. Two parallel streams of research are the study of model surfaces consisting of single crystal or polished polycrystalline surfaces 2,[11][12][13][14][15][16][17][18]23 and the study of highly dispersed catalysts incorporated into fuel cell membrane electrode assemblies (MEAs). 2,5,7,10,19,20,21,23 In a DMFC MEA, the catalytic particles are coated with Nafion, which doubles as the polymer electrolyte and the catalyst binder.…”

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confidence: 99%

Methanol Oxidation on Nation Spin-Coated Polycrystalline Platinum and Platinum Alloys

Liu

Viswanathan

Liu

et al. 1999

Electrochem. Solid-State Lett.

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Linear sweep voltammetry (0-0.8 V vs. RHE) of polished polycrystalline Pt electrodes in 2 M methanol/1 M perchloric acid shows no methanol oxidation at potentials more negative than 0.6 V, and barely discernable methanol oxidation at 0.8 V, without prior cyclic voltammetric (CV) activation, even at scan rates up to 10 V/s. Spin-coating a thin Nafion film onto the electrode enables a first scan methanol oxidation onset at 0.4 V, with an order of magnitude enhancement for methanol oxidation at 0.8 V without prior cyclic voltammetric activation. The Nafion film apparently prevents poisoning of the surface by CO, and allows one to observe dual pathway methanol oxidation at low overpotential in the first CV scan. Because CV activation is not required, the same procedure can be used to study methanol oxidation at Nafion-coated alloy electrodes (Pt(50)Ru(50) and Pt(65)Ru(25)Os (10)). These electrodes were compared to Pt in 2 M methanol/0.5 M H 2 SO 4 at 50°C. The onset of anodic current attributed to methanol oxidation occurs at more negative potentials with the alloy electrodes than with pure Pt.

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“…Raman spectroscopy showed that CO oxidation becomes slower on a highly rough surface, i.e., a surface with more defects, such as edges, kinks and step sites, than on a less rough surface. Beden et al 3,7 studied the electroadsorption and oxidation of methanol on smooth and rough polycrystalline, single crystalline and preferentially oriented Pt electrodes using electromodulated infrared spectroscopy (EMIRS). They found that poisoning by CO was reduced on electrodispersed Pt (roughness factor 20) in comparison to smooth Pt, indicating that the structure of the surface plays an important role in diminishing the phenomena of CO ad poisoning.…”

Section: Introductionmentioning

confidence: 99%

“…Considered as a poten-846 STEVANOVI et al tial fuel for fuel cells, studies of its oxidation on Pt and supported Pt catalysts have intensified during the last decades. The overall reaction: CH 3 OH + H 2 O CO 2 + 6H + + 6e - (1) occurs in several steps 1-3 but the two main processes are adsorption followed by dehydrogenation of methanol and oxidation of CO ad . 1 Oxidation of CO ad commences when oxygen-containing species are produced in the interaction of water with platinum.…”

Section: Introductionmentioning

confidence: 99%

Influence of surface morphology on methanol oxidation at a glassy carbon-supported pt catalyst

Stevanović

Tripković

Kowal

et al. 2008

JSCS

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Platinum supported on glassy carbon (GC) was used as a model system for studying the influence of the surface morphology of a Pt catalyst on methanol oxidation in alkaline and acidic solutions. Platinum was deposited by the potential step method on GC samples from H 2 SO 4 + H 2 PtCl 6 solution under the same conditions with loadings from 10 to 80 g cm -2 . AFM and STM images of the GC/Pt electrodes showed that the Pt was deposited in the form of 3D agglomerates composed of spherical particles. Longer deposition times resulted in increased growth of Pt forms and a decrease in the specific area of the Pt. The real surface area of Pt increased with loading but the changes were almost negligible at higher loadings. Nevertheless, both the specific and mass activity of platinum supported on glassy carbon for methanol oxidation in acidic and in alkaline solutions exhibit a volcanic dependence with respect to the platinum loading. The increase in the activity can be explained by the increasing the particle size with the loading and thus an increase in the contiguous Pt sites available for adsorption and decomposition of methanol. However, the decrease in the activity of the catalyst with further increase of loading and particle size after reaching the maximum is related to the decrease of active sites available for methanol adsorption and their accessibility as a result of more close proximity and pronounced coalescence of the Pt particles.

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Chemisorption of methanol on different platinum electrodes (smooth and rough polycrystalline, monocrystalline, and preferentially oriented), as studied by EMIRS

Cited by 44 publications

References 19 publications

3D Electrodes from aluminium foams prepared by replication process

3D Electrodes from aluminium foams prepared by replication process

Methanol Oxidation on Nation Spin-Coated Polycrystalline Platinum and Platinum Alloys

Influence of surface morphology on methanol oxidation at a glassy carbon-supported pt catalyst

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