Pt/Carbon electrocatalysts functionalized with phenylsulfonic acid and perfluorooctylphenyl groups.
Pt/carbon electrocatalysts that have been functionalized via diazonium-based chem. with phenylsulfonic acid and perfluorooctylphenyl groups show a variety of interesting properties, and these electrocatalysts can help us understand the impact of catalyst support surface properties on electrode performance and durability. For example, we have found that the presence of phenylsulfonic acid groups on the surface of Pt/Vulcan improves the electrode proton cond., but the electrode will then tend to flood even at low ionomer content (I/C = 0.4). The presence of hydrophobic perfluorooctylphenyl groups on the surface of Pt/Vulcan results in behavior similar to unmodified Pt/graphitized-Vulcan. Preliminary results indicate that at least some of these effects are due to changes in ink properties that influence the microstructure of the catalyst layer in the MEA. [on SciFinder(R)]