Carbon supported Pt-Sn alloy catalysts were prepared by reduction of Pt and Sn precursors with formic acid. Modifying the Pt/Sn ratio and the reducing agent concentration significantly influences the cell performance and product distribution of the cell. A physicochemical investigation was carried out to support the interpretation of electrochemical results. Chronoamperometries carried out at 70°C and 90° C allowed it to identify the reaction products of ethanol electro-oxidation and their distribution for different catalyst catalysts. Optimum catalyst composition in terms of cell performance was found to be a Pt/Sn ratio of 3:1, even though large amounts of incomplete oxidation products are still produced.