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    • Keywords


      Cyclic voltammetry; electrochemical impedance spectroscopy; activation energy; fuel cell; alcohol.

    • Abstract


      Temperature dependence on the electro-oxidation of methanol, ethanol and 1-propanol in 0.5 M H2SO4 were investigated with Pt and PtRu electrodes. Tafel slope and apparent activation energy were evaluated from the cyclic voltammetric data in the low potential region ($0.3-0.5$ V vs SHE). The CV results provided Tafel slopes for alcohols in the range of 200-400 mV dec-1 which indicated a difference in the rate determining step. The decrease in Tafel slope was only observed in the case of methanol for the Ru-modified Pt electrode. This indicates that Ru improves the rate of determining step for methanol while hindering it for the other alcohols. The electrochemical impedance spectroscopy was also used to evaluate the electro-oxidation mechanism of alcohols on these electrodes. The simulated EIS results provided two important parameters: charge transfer resistance ($R_{ct}$) and inductance (𝐿). The $R^{-1}_{ct}$ and $L^{-1}$ represent the rate of alcohol electro-oxidation and rate of desorption of intermediate species, respectively. These values increased with the increasing of temperature. The results from two techniques were well agreed that the electro-oxidation of methanol was improved by raising the temperature and ruthenium modification.

    • Author Affiliations


      Panadda Katikawong1 Tanakorn Ratana2 Waret Veerasai1

      1. Department of Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
      2. Department of Industrial Chemistry, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800, Thailand
    • Dates

  • Journal of Chemical Sciences | News

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