Preparation of Pt–Ru bimetallic anodes by galvanostatic pulse electrodeposition: characterization and application to the direct methanol fuel cell.

The electrodeposition of platinum and ruthenium was carried out on carbon electrodes to prepare methanol anodes with different Pt/Ru atomic ratios using a galvanostatic pulse technique. Characterizations by XRD, TEM, EDX and atomic absorption spectroscopy indicated that most of the electrocatalytic anodes consisted of 2 mg cm-2 of Pt–Ru alloy particles with the desired composition and with particle sizes ranging from 5 to 8 nm. Electrochemical tests in a single DMFC show that these electrodes are very active for methanol oxidation and that the best Pt/Ru atomic ratio in the temperature range used (50–110 °C) is 80:20. The influence of the relaxation time toff was also studied and it appeared that a low toff led to smaller particle sizes and higher performances in terms of current density and power density. [ABSTRACT FROM AUTHOR]