Highly-efficient buckypaper paper-based electrodes for PEMFC

The Pt catalytic electrode was developed using carbon nanotube film (buckypaper) as a supporting medium through use of the electrodeposition method. Buckypapers are free-standing thin films consisting of single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT) or carbon nanofibeis (CNF) held together by van der Waals forces without any chemical binders. Mixed buckypapers may be developed by layered microstructures with a dense and high-conducting SWNT networks at the surface, as well as large porous structures of MWNT or CNF networks as supports. This unique microstructure may improve Pt catalyst accessibility and the mass exchange properties. Pt particles were uniformly deposited in porous buckypaper and had an average particle size of about 6 nm. A promising electrochemical surface area of about 40 m² g^-1 was obtained from these electrodes. A Pt utilization of as low as 0.5 g kW^-1 was achieved for the cathode electrode at 80°C. Pt utilization efficiency may be further improved by optimization of the electrodeposition condition in order to reduce the Pt particle size.