| abstract |
Electrodes for polymer electrolyte membrane and direct methanol fuel cells comprise carbon nanotubes and catalytically active metal. In one embodiment, anode electrodes are prepared by depositing catalytic metal on carbon nanotubes, and forming the carbon nanotubes into a membrane. Anode electrodes comprising carbon nanotubes provide higher fuel cell performance with a much lower platinum loading than conventional carbon-based electrode material having a much higher platinum loading. In another embodiment, a catalyst ink comprising carbon nanotubes and a catalytic metal-loaded carbon powder was used to form an electrode membrane. The catalyst ink comprising carbon nanotubes and catalyst-loaded carbon powder can optionally comprise an ionically conductive polymer, such as a perfluorosulfonic acid/PTFE copolymer. In another embodiment, a fuel cell electrode comprising carbon nanotubes and catalytically active metal is a free standing electrode. In another embodiment of a membrane electrode assembly, carbon nanotubes are sandwiched between a catalyst-loaded electrode and a polymer electrolyte membrane. |