Effect of fluorine-oxygen mixed gas treated graphite fibers on electrochemical behaviors of platinum-ruthenium nanoparticles toward methanol oxidation

In the present study, graphite fibers (GFs) were treated with fluorine-oxygen mixed gas with changing gas treatment temperatures to study the effect of surface modification. Treated GFs-supported platinum (Pt)/ruthenium (Ru) catalysts were prepared to check the influence of gas treatment on electroactivity of metal catalysts. The crystalline size and the surface compositions of the carbon-supported catalysts were determined by XRD and XPS, respectively. Electrochemical properties of the electrocatalysts were analyzed by cyclic voltammetry (CV) measurements. When gas-treated GFs were used as a catalyst support, the current density for a methanol oxidation was greater than that of pristine catalyst; meaning the treated GFs-supported catalysts had a higher electroactivity. These results were in agreement with CV results that confirmed the greater effective electrochemical surface area for a hydrogen adsorption-desorption reaction of catalysts, which was originated from smaller particle size.