Ionic liquid-assisted synthesis of Pt nanoparticles onto exfoliated graphite nanoplatelets for fuel cells.

Exfoliated graphite nanoplatelets (GnP) has been investigated as an electrocatalyst support for fuel cell applications. GnP-supported Pt catalysts were synthesized by a microwave process in the presence of room temperature ionic liquids (RTILs). Thermal-oxidation resistance of GnP and GnP-supported Pt catalysts was studied by thermogravimetric analysis and compared with a variety of other carbon nanostructures: carbon black, graphite nanofiber, single- and multiwalled carbon nanotubes. GnP showed the best thermal-oxidative stability. The results obtained from X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, scanning and transmission electron microscopy showed that the RTIL synthesis method resulted in size reduction of Pt nanoparticle, improvement of Pt dispersion on GnP, and identification of the relationships between the mean size of Pt particles with increasing RTIL content. The interaction of Pt particles-GnP is stronger than that of a commercial Pt-CB, and the Pt/GnP catalysts prepared by this method have excellent electrocatalytic activity and stability for methanol oxidation.