Electro-Oxidation of Methanol on PtRu Nanostructured Catalysts Electrodeposited onto Electroactivated Carbon Fiber Materials

Abstract

The surface of different carbon substrates, such as glassy carbon (GC), graphite cloth (GC-10), graphite felt (GF-S2), and carbon fiber paper (CFP) was modified by electrochemical treatment to generate high concentrations of oxygenated functional groups. These activated carbons were used as substrates for the simultaneous electrodeposition of Pt and Ru by a double potentiostatic pulse program. The different catalyst/carbon systems were evaluated as electrodes for methanol oxidation in acid solution. Comparing the results for the oxidized and nonoxidized substrates, the oxidation of the different carbon materials prior to the catalyst deposition was found to lead to an increase in the electrode activity for methanol oxidation. This enhancement could be associated with a remarkable improvement of metal dispersion, reduction of particle size, and a higher active surface area of the catalyst. The electrodes prepared with oxidized graphite felt exhibited the greatest catalytic activity.