Synthesis And Electrocatalytic Performance Of Pt Supported On Carbon Fiber Based Composites

Direct methanol fuel cell(DMFC)represents the various advantages of fuel cell technology,thus draws more and more attentions in fixed and mobile power applications.The activity and stability of the electrocatalyst are important factors to promote the commercialization of DMFC.As is well known,the performance of the electrocatalyst is closely related to the properties of the supporting materials.Carbon nanofiber possesses large surface area,stable physical and chemical properties,and it also could easily hybrid with other substances and can be used as a promising support material for fuel cell catalyst.In this paper,simple and efficient electrospinning technology was adopted to fabricate series of carbon nanofiber composites using polyacrylonitrile(PAN)+ oxidatized coal,PAN + graphene oxide(GO)and PAN + polyvinylpyrrolidone(PVP)as precursor,respectively.And the papered series carbon nanofiber composites were used as the supporting materials to synthetize the supported Pt electrocatalyst,the catalystic performance of the obtained supported Pt electrocatalyst towards methanol oxidation(MOR)and oxygen reduction reaction(ORR)were investigated in details.The main research results are as follows:1.Carbon nanofiber(CF),coal-based carbon nanofiber(coal-CF),Co embedded carbon nanofiber(Co-CF)and Co embedded coal-based carbon nanofiber(Co-coal-CF)were respectively fabricated by electrospinning of spinning dope containing PAN,PAN + oxidized coal,PAN + CoAc or PAN + CoAc + oxidized coal,followed by carbonization process.And then the Pt nanoparticles were deposited on CF,coal-CF,Co-CF and Co-coal-CF to fabricate the supported Pt electrcatalyst: Pt/CF,Pt/coal-CF,Pt/Co-CF and Pt/Co-coal-CF.Physical and chemical characterization and electrochemical performance results showd that the synergetic effect of Co-coal-CF lead to the well dispersion of Pt,and the obtained Pt/Co-coal-CF had better CO tolerance,the high catalytic activity(92.7A?g-1)and stability towads MOR.2.Electrospinning and chemical reduction combined with electrospinning were used respectively to construct carbon hybrids: graphene incorporated carbon fiber(RGO-CF)and graphene intercalated carbon fiber(RGO/CF)hybrid materials.And the two hybrids were used to support Pt nanoparticles respectively and prepared the corresponding Pt/RGO-CF or Pt/RGO/CF catalyst.Series of characterization results revealed that RGO/CF could offer rich nitrogen and oxygen functional groups,lower charge transfer resistance as well as strong interaction between Pt and the hybrid support,therefore,Pt/RGO/CF demonstrated outstanding catalytic performance toward MOR and ORR.Meanwhile,Pt/RGO/CF also exhibited superior stability on MOR and ORR to commercially available Pt/C.3.Series of PCFx(x represents the mass ratio of PVP and PAN)composites derived from PAN and PVP were fabricated and used to immobilize Pt nanoparticles for getting Pt/PCFx electrocatalysts.Preliminary study results show that the prepared PCF material by adding appropriate PVP into PAN spinning dope would enhance the MOR activity and stability of Pt supported on PCF.