Ethanol‐tolerant Pt‐alloy cathodes for direct ethanol fuel cell (DEFC) applications

The electroactivity of Pt 1 Co 1 (a/o)/C and Pt 3 Cr 1 (a/o)/C for the oxygen reduction reaction (ORR) in ethanol‐containing medium was studied. It was found that these cathodes present a high tolerance to this alcohol. The onset potential of the ORR decreased at 14 and 12 mV in the presence of 0.5 M ethanol on Pt 1 Co 1 /C and Pt 3 Cr 1 /C, respectively. The tolerance of the Pt alloys is one order of magnitude higher than that shown by Pt‐alone catalysts in previous works. Exceptionally, the Pt 1 Co 1 /C alloy maintained a very important electrocatalytic activity, i.e. a very small variation in current density at 400 mV in electrochemical cell measurements and improved performances in a direct ethanol fuel cell (DEFC). The current densities obtained from the DEFC equipped with a 10% Pt 1 Co 1 /C cathode were similar to those obtained when 20% Pt 3 Cr 1 /C was used. However, a higher performance in terms of Pt content was shown by PtCo/C. These electrochemical characteristics indicate the advantage of using PtCo alloys as cathodes in DEFCs. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.