Investigation of the Electrochemical Behavior of Potential Denaturing Agents for Ethanol Compatible with the Use in Direct Ethanol Fuel Cells

In order to be tax free, the ethanol for use in direct ethanol fuel cells (DEFC) needs to be denatured. The electrochemical behavior of a number of potential denaturing agents was therefore studied with respect to their compatibility with DEFC operation. Tests comprised the investigation of the denaturing agents' oxidation at platinum model electrodes, their influence on the ethanol oxidation at platinum model electrodes and at fuel cell catalysts as well as the analysis of the products which get formed. Cyclic voltammetry, chronoamperometry and differential electrochemical mass spectrometry were used as methods. Eventually, a mixture of ethyl-tert-butyl ether and Bitrex® was found which should qualify as denaturing agent and did not show any severe detrimental effect on electrochemical reactions important for DEFC operation.