Publicação
Evaluation of Catalytic Activity of Pt and Pt-Ru Catalysts for Electro-oxidation of Methanol in Acid Medium by Cyclic Voltammetry
| Resumo: | 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 |
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| Autores principais: | Khan,A. S. A. |
| Outros Autores: | Ahmed,Riaz; Mirza,M. Latif |
| Assunto: | methanol acid medium cyclic voltammetry catalytic activity kinetics thermodynamic |
| Ano: | 2009 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Fundação para a Ciência e Tecnologia |
| Idioma: | inglês |
| Origem: | SciELO Portugal |
| Resumo: | 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 |
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