Porous Pt-Decorated Graphene Based Cathode Encaged by MWCNT Network in PEMFC

초록

Proton exchange membrane fuel cells (PEMFCs) using hydrogen as a fuel are being developed to replace batteries in portable electronic devices and internal combustion engines on account of their high energy effrciency, low pollutant emission and low working temperature. To effectively utilize the Pt electro-catalysts, Pt must have simultaneous access to the gas, electron-conducting medium, ffid proton-conducting medium. Therefore, the catalyst layers must be relatively thin and porous to minimize the losses due to the rate of proton diffusion within the catalyst layer and the rate of mass transfer of the chemical reactants and products to and from the active sites. This study examinedp orous Pt-graphene/multiwalledc arbonn anotube( MWCNT) composite cathodes prepared for PEMFCs along with their electro-chemical performance. As a result, the porous MWCNT network enabled the Pt-graphene electrode to overcome the deficiency OF 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 a Pt-graphene cathode, and the maximum power density of the Pt-graphene/MWcNT composite cathodew as four times higher than that of a Pt-graphenec athode.