Title of article :
Electrocatalytic performance of different Mo-phases obtained during the preparation of innovative Pt-MoC catalysts for DMFC anode
Author/Authors :
Guillén-Villafuerte، نويسنده , , O. and Guil-Lَpez، نويسنده , , R. and Nieto، نويسنده , , E. and Garcيa، نويسنده , , G. and Rodrيguez، نويسنده , , J.L. and Pastor، نويسنده , , E. and Fierro، نويسنده , , J.L.G.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Pages :
9
From page :
7171
To page :
7179
Abstract :
Electrochemical studies of new binary Pt-MoC electrocatalysts prepared by carbothermal-reduction method have been developed. The XRD and XPS characterization allows to determine the structure of core–shell Mocarb-particles, with a reduced-Mo core (Mo2C, MoO2 and/or Mo0) and a MoO3-shell (2–3 nm). Upon adding Pt, Pt interacts with MoO3-shell. idation of: (i), CO by cyclic voltamperometry (CV) followed by in situ differential electrochemical mass spectrometry (DEMS); and, (ii), methanol by CV and chronoamperometric techniques were carried out at room temperature. The results show an improvement in the Pt-tolerance to CO-presence with the presence of reduced Mocarb phases (decreasing the potential in 65 mV RHE), without significant difference between the binary catalysts. An additional Mo-redox pre-peak is observed at 0.4RHE V. This process is related to Mo4+-to-Mo6+ oxidation developed on the MoO3-shell of Mocarb-particles, which is catalysed by Pt. This Mo-oxidation/reduction couple is affected (shifts towards more negative potentials) by the CO adsorption on Pt-centres. DEMS results show that CO-oxidation occurs in the potential region of this Mo-oxidation. nary Pt-Mocarb catalysts show similar behaviour for methanol oxidation as those for CO-stripping ones. Nevertheless, the chronoamperometric curves display a catalytic performance improvement (highest activity and stability) using Pt-MoC/CBv catalyst regarding the other binary catalysts. This best behaviour with Mo2C-phase enhances to increases the temperature up to 60 °C (typical value for low-temperature FCs in-operation).
Keywords :
Binary Pt-MoC electrocatalysts , chronoamperometry , DEMs , MeOH oxidation , CO-Stripping , Cyclic voltammetry
Journal title :
International Journal of Hydrogen Energy
Serial Year :
2012
Journal title :
International Journal of Hydrogen Energy
Record number :
1671150
Link To Document :
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