Electrochimica Acta 49 (2004) 3901–3908 Recent progress in the direct ethanol fuel cell: development of new platinum–tin electrocatalysts C. Lamy 1 , S. Rousseau, E.M. Belgsir, C. Coutanceau, J.-M. Léger ∗,1 UMR 6503, Equipe Electrocatalyse, CNRS-Université de Poitiers 40, Avenue du Recteur Pineau, 86022 Poitiers Cedex, France Received 2 November 2003; received in revised form 20 December 2003; accepted 21 January 2004 Available online 5 June 2004 Abstract 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 ac- tivity is greatly enhanced at low potentials. The optimum composition in tin is in the range 10–20at.%. With this composition, it was demonstrated that poisoning by adsorbed CO coming from the ethanol dissociative chemisorption is greatly reduced leading to a signif- icant 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. © 2004 Published by Elsevier Ltd. Keywords: Ethanol; Fuel cell; Electrooxidation; Platinum–tin; Poisoning effect 1. Introduction In various applications, fuel cells are widely recognized as very attractive devices to obtain directly electric energy from the combustion of a chemical product. Low temper- ature fuel cells, generally conceived around a proton elec- trolyte membrane, seem able to be used for a large range of power applications. However, the final choice of the fuel is still difficult and depends greatly on the field of appli- cation. If hydrogen or hydrogen-rich gas obtained by fuel reforming are clearly the best choices for stationary appli- cations, the problem related to hydrogen storage for mobile application leads to the necessity to look for alternative fuels convenient to be used directly in fuel cells. The direct use of organic fuels have been often considered despite of their rather low electrochemical reactivity in comparison to hy- drogen. Alcohols and mainly methanol are widely proposed ∗ Corresponding author. Tel.: +33-5-4945-3970; fax: +49-5-4945-3580. E-mail address: jean.michel.leger@univ-poitiers.fr (J.-M. L´ eger). 1 ISE member. as possible fuels for mobile applications such as electric ve- hicles [1–3]. One of the main advantages of methanol is its availability, its low price and the easiness of its storage as a liquid. A huge literature concerns the possibility to improve its electroreactivity by using platinum-based electrocatalysts [4]. However, the question of the toxicity of methanol re- mains crucial. Methanol is considered since a long time as a toxic product (mainly neurotoxic), in addition to possible environmental problems in relation to its large miscibility to water. However, methanol remains a very attractive fuel, even if it is necessary to be cautious. As examples, for portable electronic devices (laptop comput- ers, cellular phones, ... ), methanol can be used if technical solutions, involving tight and/or disposable reservoirs, are found. Another alternative is to use other alcohols pre- senting negligible or very low chemical toxicity which is essential, at least for some applications. Ethanol appears to be an interesting alternative fuel for a wide utilization, even if its price appears actually too high. Its low toxi- city added to its availability (from biomass products) is an important positive point for its use as an alternative 0013-4686/$ – see front matter © 2004 Published by Elsevier Ltd. doi:10.1016/j.electacta.2004.01.078