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2010
Conference Paper
Titel
Concentration dependence of the electro-oxidation of ethanol and ethylene glycol at platinum in alkaline medium
Abstract
In the present work, the electro-oxidation of ethanol and ethylene glycol in alkaline medium is studied depending on their concentration by cyclic voltammetry, chronoamperometry and differential electrochemical mass spectrometry (DEMS). It is shown that in the case of ethanol, carbon dioxide as product of the oxidation can only be found during cyclic voltammetry. Within the investigated concentration range, potentiostatic experiments do not indicate bulk oxidation of ethanol to carbon dioxide. For ethylene glycol, the oxidation in cyclic voltammetry as well as in chronoamperometric experiments leads to significant carbon dioxide formation with the tendency that low concentrations and low potentials yield high carbon dioxide current efficiencies. Furthermore, comparatively higher current densities in cyclic voltammetry and chronoamperometric experiments indicate that with respect to ethanol, ethylene glycol is more active and the poisoning effect on platinum in alkaline medium is less severe.