Effect of electrochemical polarization of PtRu/C catalysts on methanol electrooxidation

Wu, Gang; Li, Li; Xu, Bin

doi:10.1016/j.electacta.2004.07.006

Cited by 221 publications

(106 citation statements)

References 47 publications

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“…The probability of cluster formation is lowered in the presence of the second metal (e.g., Ru), which, for a high second-metal content, is expected to lead to a change in the RDS from CO oxidation to CO formation [10,12,13]. Similar reasoning has been used to explain the optimal PtRu composition for methanol oxidation [14]. In agreement with this interpretation, Liu et al found that, in spite of decreasing the onset potential of DME on Pt/C to 57 kJ mol −1 on PtRu/C [10].…”

Section: Ddmefc Tests With Different Ptru Catalystsmentioning

confidence: 81%

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Direct Dimethyl Ether Fuel Cell with Much Improved Performance

Johnston

et al. 2014

Electrocatalysis

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Due to several apparent advantages over methanol, dimethyl ether (DME) has been viewed as a promising alternative fuel for direct fuel cell technology. Similar to methanol, DME oxidation requires a surface oxidant, such as OH, for the removal of adsorbed CO. Consequently, the reaction occurs at much faster rates on binary PtRu catalysts than Pt alone. In this work, PtRu catalysts with a wide variety of Pt-to-Ru ratios were systematically studied in the direct DME fuel cell (DDMEFC) operating at 80°C. A Pt 50 Ru 50 catalyst was found to perform the best at high and middle voltages, while a Pt 80 Ru 20 catalyst performed best at low voltages. DDMEFC operation conditions, such as DME flow rate, anode back pressure, DME-to-water molar ratio, and membrane thickness, were also studied in order to maximize the cell performance. A maximum power density of 0.12 W cm −2 obtained in this work exceeds the highest reported DME performance.In comparison with the direct methanol fuel cell (DMFC), the optimized DDMEFC performs better at cell voltages higher than 0.55 and 0.49 V with feed concentrations of methanol of 0.5 and 1.0 M, respectively.

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Section: Ddmefc Tests With Different Ptru Catalystsmentioning

confidence: 81%

“…The deactivation is more severe for Rurich than Pt-rich catalysts. The effect can be ascribed to more facile oxide formation of the surface of Ru-rich catalysts and possibly also due to Ru dissolution [14].…”

Section: Ddmefc Tests With Different Ptru Catalystsmentioning

confidence: 99%

Direct Dimethyl Ether Fuel Cell with Much Improved Performance

Johnston

et al. 2014

Electrocatalysis

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“…The ligand effect assumes that the energy level of the metal catalyst is modified so that the binding strength with the metal and adsorbed CO is weakened, resulting in a reduction in overpotential for CO oxidation. The possibility that some nanostructured ruthenium oxides (expressed as RuO x H y or RuO 2 •xH 2 O in the literature) may act as co-catalysts has attracted interest and debate [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Several studies have suggested that the binary PtRu alloy structure is not a prerequisite for obtaining the highest activity, and partially oxidized ruthenium species (RuO x ) that are present in the PtRu/C catalysts may contribute to the anodic activity [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Enhanced activity and stability of Pt/C fuel cell anodes by the modification with ruthenium-oxide nanosheets

Saida¹,

Sugimoto²,

Takasu³

2010

Electrochimica Acta

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Ruthenium oxide nanosheet (RuO 2 ns) crystallites with thickness less than 1 nm were prepared via chemical exfoliation of a layered potassium ruthenate and deposited onto carbon supported platinum (Pt/C) as a potential co-catalyst for fuel cell anode catalysts. The electrocatalytic activity towards carbon monoxide and methanol oxidation was studied at various temperatures with for different RuO 2 ns loadings. An increase in electrocatalytic activity was evidenced at temperatures above 40°C, while little enhancement in activity was observed at room temperature. The RuO 2 ns modified Pt/C catalyst with composition of RuO 2 :Pt= 0.5:1 (molar ratio) exhibited the highest methanol oxidation activity. CO-stripping voltammetry revealed that RuO 2 ns promotes oxidation of adsorbed CO on Pt. In addition to the enhanced initial activity, the RuO 2 ns modified Pt/C catalyst exhibited improved stability compared to pristine Pt/C against consecutive potential cycling tests.

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“…The decrease in Tafel slope with increase of temperature has been reported in literature for PtRu/C when the catalyst was incorporated in the MEA with Nafion as electrolyte. 38 Each of the Nyquist plots at 80°C from the impedance spectroscopy of methanol oxidation at different dc potentials shows a capacitive loop in the first quadrant and another pseudoinductive loop in the forth quadrant ͑Fig. 9͒.…”

Section: Resultsmentioning

confidence: 99%

Mixed Phase Pt-Ru Catalyst for Direct Methanol Fuel Cell Anode by Flame Aerosol Synthesis

Chakraborty

Bischoff

Chorkendorff

et al. 2005

J. Electrochem. Soc.

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A spray-flame aerosol catalyzation technique was studied for producing Pt-Ru anode electrodes for the direct methanol fuel cell. Catalysts were produced as aerosol nanoparticles in a spray-flame reactor and deposited directly as a thin layer on the gas diffusion layer. The as-prepared catalyst was found to be a mixture of nanocrystalline, mostly unalloyed Pt and an amorphous phase mostly of Ru and to a lesser extent of Pt oxides on top of the crystalline phase. The flame-produced Pt1Ru1 demonstrated similar onset potential but ∼60% higher activity compared to commercially available Pt1Ru1/Vulcan carbon. The kinetics of methanol oxidation on the mixed phase catalyst was also explored by electrochemical impedance spectroscopy.

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Effect of electrochemical polarization of PtRu/C catalysts on methanol electrooxidation

Cited by 221 publications

References 47 publications

Direct Dimethyl Ether Fuel Cell with Much Improved Performance

Direct Dimethyl Ether Fuel Cell with Much Improved Performance

Enhanced activity and stability of Pt/C fuel cell anodes by the modification with ruthenium-oxide nanosheets

Mixed Phase Pt-Ru Catalyst for Direct Methanol Fuel Cell Anode by Flame Aerosol Synthesis

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