Effect of the Iridium Oxide Thin Film on the Electrochemical Activity of Platinum Nanoparticles

Chen, Aicheng; Russa, D La; Miller, B.

doi:10.1021/la0484873

Cited by 125 publications

(91 citation statements)

References 41 publications

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“…Even if there is no good correlation between the CO adsorption and electrochemically active surface area, there is a clear difference in the shape of the CO-stripping peak for Pt and PtIr. Chen et al showed in their study that the H UPD charges and the CO-stripping charges gave similar values for the electrochemically active surface area of electrodes with Pt deposited on Ir oxide, assuming linearly bonded CO [51]. However, for the 3Pt3Ir electrodes covered with Nafion used in this work, the H UPD charges are very low which is similar to observations made by Slavcheva et al where diminishing H UPD charges on sputtered electrodes with Pt and Ir oxide with increasing hydration of the Ir oxide layer was seen [29].…”

Section: Electrochemical Resultsmentioning

confidence: 86%

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

Wesselmark¹,

Wickman²,

Lagergren³

et al. 2013

Electrochimica Acta

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a b s t r a c tIncreasing the stability and lifetime of the electrodes is one of the most important factors in order to realise a large scale use of polymer electrolyte membrane fuel cells (PEMFC). By using well-defined thin-film model electrodes, the stability of Pt and Pt on Ir were examined as cathode catalysts in a single cell PEMFC setup. The electrodes were fabricated by evaporating thin layers of Pt and Pt on Ir onto the microporous layer of a gas diffusion layer. The amount of Pt deposited was equivalent to 3 nm (about 6.3 g cm −2 ) and the amount of Ir was varied between 1.5 nm and 20 nm (between 3.4 g cm −2 and 45.3 g cm −2 ). All samples with Ir showed an increased stability over samples with sole Pt during cyclic corrosion test between 0.6 V and 1.2 V vs. the reversible hydrogen electrode. For thin layers of Ir, the initial activity for the oxygen reduction reaction was equal to or superior to that of sole Pt but for thicker Ir films it was somewhat lower. Hydrogen underpotential deposition and CO stripping were used to estimate the electrochemical surface area during the experiments and physical characterisation using scanning electron microscopy and X-ray photoelectron spectroscopy were used to determine the structure of the samples. The results suggest that Ir can stabilise Pt in the cathode electrode.

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Section: Electrochemical Resultsmentioning

confidence: 86%

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

Wesselmark¹,

Wickman²,

Lagergren³

et al. 2013

Electrochimica Acta

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show abstract

“…Electrochemical impedance spectroscopy has been a powerful and sensitive technique to study electrochemical kinetics, for instance, in the investigations of the electro-oxidation process of small organic molecules in fuel cells. [45][46][47][48] From the voltammetric studies presented above, it can be seen that the loading of the FePt nanoparticle catalysts strongly affects the electrochemical reaction dynamics of formic acid oxidation, which were further examined by EIS measurements, as presented below. Figure 5 shows the Nyquist complex-plane impedance spectra of the electrodes with one, two, and four FePt particle layers in 0.1 M HCOOH and 0.1 M HClO 4 at varied electrode potentials from -0.3 to +0.9 V (shown as figure legends).…”

Section: Electrochemistry Of Ptfe Functionalized Electrodesmentioning

confidence: 99%

Langmuir−Blodgett Thin Films of Fe₂₀Pt₈₀ Nanoparticles for the Electrocatalytic Oxidation of Formic Acid

Chen

Kim

et al. 2007

J. Phys. Chem. C

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The electro-oxidation of formic acid catalyzed by Fe 20 Pt 80 nanoparticles was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) where the particles were deposited onto a gold electrode surface by the Langmuir-Blodgett (LB) technique at varied film thickness/coverage. It was found that the particle assembly thickness strongly affected the electrocatalytic activity for HCOOH oxidation. For a single monolayer and two layers of FePt particles, extensive CO adsorption (poisoning) was observed in CV measurements, whereas with a four-layer assembly of the FePt particles, the tolerance to CO poisoning improved drastically. Furthermore, from the current density for formic acid oxidation, the electrodes functionalized with LB layers of nanoparticles exhibited higher activities than those with dropcast films of similar thickness, suggesting the importance of the ordering of the particle layers in the electrocatalytic performance. The reaction kinetics in the HCOOH oxidation on the three kinds of particle film-modified electrodes was then examined by EIS measurements. It was found that except within the potential range for CO oxidation, the impedance spectra behaved normally with the responses shown in the first quadrant for all three nanoparticle assemblies under study, indicative of only resistive and capacitive components in the electrochemical cell. In contrast, at potentials of CO electro-oxidation, the impedance spectra were found to migrate from the first quadrant to the second quadrant and then back to the first quadrant with increasing electrode potential, which suggests that the reaction kinetics evolve from resistive to pseudoinductive and then to inductive behaviors. The different EIS behaviors are ascribed to the different degree of tolerance to CO poisoning, consistent with the voltammetric results.

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“…The addition of IrO 2 to Pt-RuO 2 shifts ethanol oxidation to lower potentials. Chen et al [24] used IrO 2 to increase the methanol oxidation rate on PtIrO 2 /C. The IrRu carbon supported/unsupported (88%Ir12%Ru)/C anodes showed higher performance than PtRu/C in DMFC [25].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells

Fatih

Neburchilov

Alzate

et al. 2010

Journal of Power Sources

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Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells Fatih, K.; Neburchilov, V.; Alzate, V.; Neagu, R.; Wang, H. 195 (2010) [7168][7169][7170][7171][7172][7173][7174][7175] Contents lists available at ScienceDirect /C electrocatalysts were prepared by a known impregnation-reduction (borohydride) method. The microstructure and chemical composition were determined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The activity of the electrocatalysts for EOR was compared to commercial Pt 67 Ru 33 /C (HISPEC5000) using linear sweep voltammetry (LSV) based on similar Pt loading. The results of this study show that electrocatalyst composition with 10 and 20% Ir (wt.%) exhibit higher electrocatalytic activity than the commercial PtRu electrocatalyst. 10 Sn 30 /C exhibited both a higher performance with a specific power density of 29 mW mg Pt −1 without O 2 backpressure at the cathode and an excellent long-term stability in a DEFC operating at 90 • C. Journal of Power Sources Journal of Power SourcesCrown

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Effect of the Iridium Oxide Thin Film on the Electrochemical Activity of Platinum Nanoparticles

Cited by 125 publications

References 41 publications

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

Langmuir−Blodgett Thin Films of Fe₂₀Pt₈₀ Nanoparticles for the Electrocatalytic Oxidation of Formic Acid

Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells

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Effect of the Iridium Oxide Thin Film on the Electrochemical Activity of Platinum Nanoparticles

Cited by 125 publications

References 41 publications

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

The impact of iridium on the stability of platinum on carbon thin-film model electrodes

Langmuir−Blodgett Thin Films of Fe20Pt80 Nanoparticles for the Electrocatalytic Oxidation of Formic Acid

Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells

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Langmuir−Blodgett Thin Films of Fe₂₀Pt₈₀ Nanoparticles for the Electrocatalytic Oxidation of Formic Acid