On the preparation and stability of bimetallic PtMo/C anodes for proton-exchange membrane fuel cells

Lebedeva, N. P.; Janssen, G.J.M.

doi:10.1016/j.electacta.2005.04.034

Cited by 95 publications

(79 citation statements)

References 25 publications

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“…3 Scanning electron microscopy and EDS analysis of a PtRh/Vulcan, b MoO 3 -modifed PtRh/Vulcan, and c WO 3 -modifed PtRh/Vulcan nanoparticles the proposed electrocatalytic system due to possible dissolution of the MoO 3 from the surface of carbon-supported PtRh nanoparticles. In the literature, the stability of MoO 3 is still controversial [62][63][64][65][66][67]. However, we have not observed any time-dependent deactivation effect that may imply dissolution of MoO 3 .…”

Section: Resultsmentioning

confidence: 42%

Enhancement of activity of PtRh nanoparticles towards oxidation of ethanol through modification with molybdenum oxide or tungsten oxide

Miecznikowski

2012

J Solid State Electrochem

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Electrocatalytic systems utilizing carbon (Vulcan)-supported PtRh nanoparticles (PtRh/Vulcan) admixed with either molybdenum oxide or tungsten oxide were tested and compared during electrooxidation of ethanol. The systems' performance was diagnosed using electrochemical techniques such as voltammetry and chronoamperometry. The proposed electrocatalytic materials were also characterized with X-ray diffraction (XRD), transmission and scanning electron microscopies (TEM and SEM), as well as SEM-coupled energy dispersive X-ray spectroscopy (SEM-EDX). For both systems containing molybdenum and tungsten oxides, enhancements in catalytic activities (relative to the behavior observed at bare PtRh/Vulcan nanoparticles) were found during ethanol electrooxidation at room temperature (22°C). Further, it was from chronoamperometric current (density)-time responses that anodic electrocatalytic currents measured at 0.3 V (vs. RHE) were more than 20% higher in the case of the MoO 3 -containing PtRh/Vulcan system relative to that utilizing WO 3 . The diagnostic "CO-stripping" experiments were consistent with the view that addition of molybdenum oxide or tungsten oxide to PtRh/Vulcan tended to shift potential for the oxidation of inhibiting CO-adsorbate ca. 80 or 40 mV towards less negative values in comparison to the analogous but oxide-free system. The fact that carbon (Vulcan)-supported PtRu nanoparticles exhibited higher electrocatalytic reactivity observed phenomena may be attributed to specific interactions between noble metal centers and the oxides in addition to chemical reactivity of metal oxo groups in the vicinity of PtRh/ Vulcan at the electrocatalytic interface.

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Section: Resultsmentioning

confidence: 42%

Enhancement of activity of PtRh nanoparticles towards oxidation of ethanol through modification with molybdenum oxide or tungsten oxide

Miecznikowski

2012

J Solid State Electrochem

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“…At the same time, the adsorption/ desorption hydrogen region increases and resembles that of a smooth platinum electrode. As can be seen from the results of Janssen et al [32,33], the nonalloyed MoO 3 phase dissolves more rapidly than Mo from the mixed Pt-MoO 3 phase. These results suggest that an increase in the Mo composition (for example PtMo (50:50)) enhances the relative stability of the catalyst or at least slows down its dissolution by forming a real Pt-Mo alloy, as shown in the binary phase diagram [25,27].…”

Section: Resultsmentioning

confidence: 81%

Electrocatalytic oxidation of ethanol on Pt–Mo bimetallic electrodes in acid medium

et al. 2006

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Pt-Mo alloy electrocatalysts were prepared by an arc-melting furnace process to investigate the origin of their enhanced activity toward ethanol oxidation. Two Mo contents were chosen in zones of the binary phase diagram where they are supposed to form either a pure alloy mixture or a solid solution. Pt-Mo alloy catalysts were more active than Pt-alone. Gradual Mo dissolution at the electrode surface was observed after voltammetric and chronoamperometric measurements. The dissolved Mo contributed to the catalytic effect of the electrode as underpotentially deposited (upd) adatoms. This dissolution probably also leads to an increase in the electrode surface roughness. Low molybdenum content in the electrode material enhances the activity toward ethanol oxidation when compared to Pt-alone. Ethanol oxidation was also investigated by in situ infrared reflectance spectroscopy in order to determine the presence of adsorbed intermediates like CO species. Acetaldehyde, acetic acid and CO 2 were also found by spectroscopic experiments.

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“…[32] The change in peak current density (0.65 V vs. SCE) of the electrooxidation of methanol is shown in Figure 4 for 240 cycles. The working period of the electrocatalyst in this specific type of measurement is proportional to the number of scan cycles; each scan cycle lasted for 2 min, and the total working period was about 8 h. The data in Figure 4 show stable electrocatalytic activity of the catalyst electrode; variation in the current density was less than 5 %.…”

Section: Dan Zhao and Bo-qing Xu*mentioning

confidence: 99%

Enhancement of Pt Utilization in Electrocatalysts by Using Gold Nanoparticles

Zhao

2006

Angew Chem Int Ed

222

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On the preparation and stability of bimetallic PtMo/C anodes for proton-exchange membrane fuel cells

Cited by 95 publications

References 25 publications

Enhancement of activity of PtRh nanoparticles towards oxidation of ethanol through modification with molybdenum oxide or tungsten oxide

Enhancement of activity of PtRh nanoparticles towards oxidation of ethanol through modification with molybdenum oxide or tungsten oxide

Electrocatalytic oxidation of ethanol on Pt–Mo bimetallic electrodes in acid medium

Enhancement of Pt Utilization in Electrocatalysts by Using Gold Nanoparticles

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