Graphite nanofibers as an electrode for fuel cell applications

The potential of graphite nanofiber supported platinum catalysts as an electrode for fuel cell applications was investigated using the electrochemical oxidation of methanol at 40 degreesC as a probe reaction. Various types of graphite nanofibers were used and the behavior of supported platinum particles on these materials compared to that when the metal was dispersed on Vulcan carbon (XC-72). Catalysts consisting of 5 wt % platinum supported on platelet and ribbon type graphite nanofibers, which expose mainly edge sites to the reactants, were found to exhibit activities comparable to that displayed by about 25 wt % platinum on Vulcan carbon. Furthermore, the graphite nanofiber supported metal particles were observed to be significantly less susceptible to CO poisoning than the traditional catalyst systems. This improvement in performance is believed to be linked to the fact that the metal particles adopt specific crystallographic orientations when dispersed on the highly tailored graphite nanofiber structures.