A. S. A. Khan,1* Riaz Ahmed,1 M. Latif Mirza2
1Fuel Cell Electrochemistry Group, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad, Pakistan
2Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
Received 27 July 2007; accepted 14 July 2009
Abstract
The cyclic voltammetric study on the electro-oxidation of methanol on 30 % Pt and 20 % Pt +10 % Ru catalysts supported on Vulcan XC-72 was carried out in 0.5 M H2SO4. Kinetic parameters such as exchange current density, Tafel slope and heterogeneous rate constants were calculated. The 30 % Pt showed a higher apparent catalytic activity for the electro-oxidation of methanol as compared with 20 % Pt + 10 % Ru catalyst. The presence of Ru did not contribute significantly towards the apparent catalytic activity of a catalyst for the electro-oxidation of methanol but it may be useful to prevent the catalyst from CO poisoning. Thermodynamic parameters, ΔH*, ΔS*, and ΔG298* have been evaluated. The values of ΔH* and ΔG298* were positive showing that the electro-oxidation of methanol is an endothermic and non-spontaneous process.
Keywords: methanol, acid medium, cyclic voltammetry, catalytic activity, kinetics, thermodynamic
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*Corresponding author. E-mail adress : abdulsattar_alikhan@email.com
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