Correlation between the carbon structures and their tolerance to carbon corrosion as catalyst supports for polymer electrolyte fuel cells

The tolerance to corrosion of cathode catalyst supports comprising carbon nanofibers with differing alignments of graphene layers was evaluated, and its correlation with structural parameters obtained from Raman spectra was discussed. The carbon nanofibers employed in this study were platelet-type carbon nanofibers (PCNF) and tubular carbon nanofibers (TCNF). The tolerance to carbon corrosion was evaluated in a membrane electrode assembly using a start-stop durability testing protocol. While the ratio of the D band peak intensity to that of the G band (I_D/I_G) does not show any correlation with tolerance to carbon corrosion, full width at half maximum of the G band (FWHM(G)) correlates well with tolerance to carbon corrosion. The results suggest that carbon materials with low FWHM(G) values are promising as cathode catalyst supports in PEFCs.