Porous graphene/carbon nanotube composite cathode for proton exchange membrane fuel cell

Porous Pt-graphene/multiwalled carbon nanotube (MWCNT) composite cathodes were fabricated for proton exchange membrane fuel cells and their electro-chemical performances were examined. Rod-like MWCNTs with a high aspect ratio induced a porous network structure and Pt-graphene was bound homogeneously to the porous network structure of MWCNTs in the form of a very rough surface, which facilitated simultaneous access between the Pt electro-catalyst and reactant. In addition, the porous MWCNT network enabled the Pt-graphene electrode to overcome the deficiency induced by high electrical resistance by providing an electrical pathway for the oxygen reduction reaction (ORR). Therefore, the ORR charge transfer resistance of the Pt-graphene/MWCNT composite cathode was much smaller than that of the Pt-graphene cathode, and the maximum power density of the Pt-graphene/MWCNT composite cathode was four times higher than that of the Pt-graphene cathode.