| Direct methanol fuel cell possesses broad application prospects as in the field ofpower source of electric vehicles and electronic equipment etc, due to the easy storageand transportation of the fuel, high energy conversion efficiency, little pollution andeasy to carry, etc. However, the slow rate of reaction kinetics of methanol at the anodeis one of technical factors of constrainting DMFC commercial production. In thispaper, we preparated novel catalyst supports which could effectively improved thedispersibility of Pt particles, and then improved the activity of catalysts.1. Novel composite electrocatalysts were prepared with Pt deposited on graphenenanoplates non-covalent modified with polyaniline(PANI) by electrostatic adsorptionand the electrocatalytic activities of Pt/PANI-G(1～5nm) and Pt/PANI-G(5～20nm)were studied. Polyaniline-graphene nanoplates composite material was prepared byin-situ polymerization, and then supported Pt. Comparing two kinds of carriermaterial preparation method, the result showed that the electrocatalytic current of theformer catalyst for methanol oxidation is higher. The crystal form, morphology andsurface chemical states of the samples(PANI0, PANI1, PANI2, PANI5) wereinvestigated by XRD, TEM, XPS and theirs electrochemical performances werediscussed by CV, EIS, CA, respectively. The catalytic activity of Pt for methanoloxidation was the best when the usage of polyaniline is2wt%, and then currentdensity was up to108mA·(mg·cm)-1.2. Graphite oxide was prepared by modified Hummers method, and graphenehydrosol was obtained using water thermal reductions from graphene oxide whichgraphite oxide was dispersed ultrasonically. Using the above method, Pt/PANI-G-1,Pt/PANI-G-2, Pt/PANI-G-3were prepared. The results shows that the current densityof Pt/PANI-G-2for methanol oxidation is the best of all, up to138mA·(mg·cm)-1.The effect of polyaniline for catalysts was discussed by XRD, TEM, XPS andelectrochemical testing.3. Using small organic molecules instead of PANI modified graphene nanoplates,Pt/amino pyrene-graphene, Pt/3,4,9,10-perylene tetracar-boxytie aciddianhydride-graphene and Pt/1,10-phenanthroline-graphene catalysts were prepared by the above-mentioned method, and theirs electrochemical performances wereinvestigated. |
