The influence of carbon nanofiber support properties on the oxygen reduction behavior in proton conducting electrolyte-based direct methanol fuel cells

Platinum nanoparticles supported on fishbone carbon nanofibers (CNFs) were synthesized and studied for the oxygen reduction reaction (ORR). The crystalline and textural properties of the CNFs were modified by synthesizing them at different temperatures, allowing the comparison of supports with either improved graphitization degree or improved porosity. A carbon black (Vulcan XC-72R) was used for comparison. Half-cell studies determined that the ORR activity is enhanced when using a CNF with improved graphitization, in contrast with CNFs with better textural properties such as surface area or pore volume. The catalysts were tested at the cathode of a direct methanol fuel cell corroborating the suitability of using highly graphitic CNFs, and a similar behavior was found in comparison with the state of the art carbon black used in this field.