The influence of different co-catalysts in Pt-based ternary and quaternary electro-catalysts on the electro-oxidation of methanol and ethanol in acid media

Salazar‐Banda, Giancarlo R.; Eguiluz, Katlin I.B.; Pupo, Marília Moura de Salles; Suffredini, Hugo B.; Calegaro, Marcelo L.; Avaca, Luís Alberto

doi:10.1016/j.jelechem.2012.01.006

Cited by 25 publications

(12 citation statements)

References 63 publications

(103 reference statements)

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“…Fundamental studies of ethanol electro-oxidation in acid media were mostly performed on platinum and its alloys [4][5][6][7][8]. Among various Pt-based binary catalysts, PtASn has been reported as the most effective for the electro-oxidation of ethanol [4,9].…”

Section: Introductionmentioning

confidence: 99%

Reaction intermediates of ethanol electro-oxidation on platinum investigated by SFG spectroscopy

Gomes

Bergamaski

Pinto

et al. 2013

Journal of Catalysis

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Although electrochemical oxidation of simple organic molecules on metal catalysts is the basic ingredient of fuel cells, which have great technological potential as a renewable source of electrical energy, the detailed reaction mechanisms are in most cases not completely understood. Here, we investigate the ethanol-platinum interface in acidic aqueous solution using infrared-visible sum frequency generation (SFG) spectroscopy and theoretical calculations of vibrational spectra in order to identify the intermediates present during the electro-oxidation of ethanol. The complex vibrational spectrum in the fingerprint region imply on the coexistence of several adsorbates. Based on spectra in ultra-high-vacuum (UHV) and electrochemical environment from the literature and our density functional theory (DFT) calculations of vibrational spectra, new adsorbed intermediates, never before observed with conventional infrared (IR) spectroscopy, are proposed here: g 2-acetaldehyde, g 2-acetyl, ethylidyne, monodentate acetate, methoxy, tertiary methanol derivative, COH residue, g 2-formaldehyde, mono and bidentate formate, CH 3 and CH 2 residues. In addition, we present new evidences for an ethoxy intermediate, a secondary ethanol derivative and an acetyl species, and we confirm the presence of previously observed adsorbates: a tertiary ethanol derivative, bidentate acetate, and CO ad. These results indicate that the platinum surface is much more reactive, and the reaction mechanism for ethanol electro-oxidation is considerably more complex than previously considered. This might be also true for many other molecule-catalyst systems.

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Section: Introductionmentioning

confidence: 99%

Reaction intermediates of ethanol electro-oxidation on platinum investigated by SFG spectroscopy

Gomes

Bergamaski

Pinto

et al. 2013

Journal of Catalysis

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“…SA (CSEM), Neuchâtel, were used as substrates for the electrocatalytic materials [42]. The boron content was ~800 ppm and the area of the working electrode exposed to the solution was 0.075…”

Section: Diamond (Bdd) Electrodes Prepared By the Centre Suisse D'elmentioning

confidence: 99%

Pt–Sn/C catalysts prepared by sodium borohydride reduction for alcohol oxidation in fuel cells: Effect of the precursor addition order

López-Suárez

Bueno‐López

Eguiluz

et al. 2014

Journal of Power Sources

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A series of Pt-Sn/C catalysts used as anodes during ethanol oxidation are synthesized by a deposition process using NaBH 4 as the reducing agent. The order in which the precursors are added affects the electrocatalytic activity and physical-chemical characteristics of the bimetallic catalysts, where the Pt-Sn catalyst prepared by co-precipitation of both metals functions best below a potential of 0.5 V and the catalyst prepared by sequential deposition of Sn and Pt (drying after Sn addition) is most active above a potential of 0.5 V. The electrochemical behavior of catalysts during ethanol oxidation in an acidic medium are characterized and monitored in a halfcell test at room temperature by cyclic voltammetry, chronoamperometry and anode potentiostatic polarization. Catalyst structure and chemical composition are investigated by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). This behavior presented for best Pt-Sn catalyst can be attributed to the so-called bifunctional mechanism and to the electronic interaction between Pt and Sn.

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“…Due to their simplicity, lightness, and operation at low temperatures, they are seen as alternative energetic routes of great viability and outcomes. Many reports have studied direct oxidation fuel cells fueled by methanol, ethanol, and ethylene glycol [2][3][4][5][6], but few studies are concerned with fuel cells using glycerol. The hindrance to extract the energy available in an alcohol is mostly caused by parallel reactions, mainly due to the poor ability of metallic surfaces to promote the cleavage of C-C bonds.…”

Section: Introductionmentioning

confidence: 99%

“…In the present study we seek, by reduction methods, to obtain Sn x @Pt y and Rh x @Pt y core-shell catalyst with different metallic proportions for an optimized glycerol oxidation reaction in acid medium, considering that the choice of catalyst synthesis methodology, and consequently, the final electrocatalyst structure obtained, is of crucial importance in the optimization of the glycerol electro-oxidation process [2][3][4][5][6][7][8][9]12]. …”

Section: Introductionmentioning

confidence: 99%

Sn@Pt and Rh@Pt core–shell nanoparticles synthesis for glycerol oxidation

et al. 2014

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The development and optimization of electrocatalysts for application in fuel cell systems have been the focus of a variety of studies where core-shell structures have been considered as a promising alternative among the materials studied. We synthesized core-shell nanoparticles of Sn x @Pt y and Rh x @Pt y (Sn@Pt, Sn@Pt 2 , Sn@Pt 3 , Rh@Pt, Rh@Pt 2 , and Rh@Pt 3 ) through a reduction methodology using sodium borohydride. These nanoparticles were electrochemically characterized by cyclic voltammetry and further analyzed by cyclic voltammetry studying their catalytic activity toward glycerol electro-oxidation; chronoamperometry and potentiostatic polarization experiments were also carried out. The physical characterization was carried out by X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The onset potential for glycerol oxidation was shifted in 130 and 120 mV on the Sn@Pt 3 /C and Rh@Pt 3 /C catalysts, respectively, compared to commercial Pt/C, while the stationary pseudo-current density, taken at 600 mV, increased 2-fold and 5-fold for these catalysts related to Pt/C, respectively. Thus, the catalysts synthesized by the developed methodology have enhanced catalytic activity toward the electro-oxidation of glycerol, representing an interesting alternative for fuel cell systems.

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The influence of different co-catalysts in Pt-based ternary and quaternary electro-catalysts on the electro-oxidation of methanol and ethanol in acid media

Cited by 25 publications

References 63 publications

Reaction intermediates of ethanol electro-oxidation on platinum investigated by SFG spectroscopy

Reaction intermediates of ethanol electro-oxidation on platinum investigated by SFG spectroscopy

Pt–Sn/C catalysts prepared by sodium borohydride reduction for alcohol oxidation in fuel cells: Effect of the precursor addition order

Sn@Pt and Rh@Pt core–shell nanoparticles synthesis for glycerol oxidation

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