High-temperature polymer electrolyte membrane based direct ethanol fuel cell

Due to its high energy density, its low toxicity and high availability ethanol would be a very suitable fuel for fuel cells in applications like portable power supply, back-up power or range-extenders. However, the complete direct conversion in low temperature type of fuel cells has yet not been demonstrated. Complete conversion in SOFC is known to be possible, however SOFC usually do not allow for frequent start-stop cycling required by the applications. HT-PEMFC based systems may thus be a good compromise. Therefore the direct oxidation of ethanol was studied at platinum and platinum alloy catalyst. For the investigation of the ethanol oxidation a special set-up was developed to perform differential electrochemical mass spectrometry in the gas phase under HT-PEMFC relevant conditions. Thus it could be shown that the addition of rhodium helped to enhance the CO2 current efficiency. Further single cell tests using single platinum and platinum alloy catalyst as well as mixtures of catalyst were performed. Here mixture of PtSn/C and PtRu/C showed high performance.