Recent progress in the direct ethanol fuel cell:: development of new platinum-tin electrocatalysts

Ethanol is an alternative choice as a fuel in a direct combustion fuel cell. Its non toxicity and its availability from biomass resources advocate its use in a direct ethanol fuel cell (DEFC), even if the actual performance obtained are slightly lower than those observed with methanol. By modifying the composition of the platinum anode by adding tin, it was confirmed that the overall electrocatalytic activity is greatly enhanced at low potentials. The optimum composition in tin is in the range 10-20 at.%. With this composition, it was demonstrated that poisoning by adsorbed CO coming from the ethanol dissociative chemisorption is greatly reduced leading to a significant enhancement of the electrode activity. However, it seems that the oxidation of ethanol is not complete leading to the formation of C2 products. These observations made in half-cell experiments are fully confirmed during electrical tests in a single direct ethanol fuel cell. (C) 2004 Published by Elsevier Ltd.