Investigation Of Low Platinum Loading Catalysts For Fell Cell

Low temperature fuel cell is a kind of fuel cell which known as the mostlarge-scale commercial production prospects,because it has the advantages of highenergy conversion efficiency, environment-friendly, removable and mild operatingconditions.Low temperature fuel cells includes proton exchange membrane fuel cells,direct methanol fuel cells and directly acids fuel cell.So far, the most effective catalysts was still platinum and its alloys, Whereas,thehigh cost and scarcity of Pt pose serious problems for the widespread commercializationof fuel cell technologies.Therefore, the development of low platinum catalysts with highperformance seems extremely important.The present work explored the preparation of the catalyst, carrier, as well as thecatalyst structure and developed low-platinum-based catalyst of the anode and thecathode of the fuel cell, and effectively reduces the amount of the noble metal platinum.For the anode of the fuel cell,we used the in situ method of preparation of cobaltnanoparticles loading on grapheme. Through the spontaneous displacement reactionbetween the cobalt particles and the chloroplatinic acid,we successfully preparedgraphene-supported platinum nanoparticles with hollow structure.Raman spectra（Raman Shift） showed that the the as prepared graphene has an ordered structure, thenumber of layers in the range of5to10. The scanning electron microscope （SEM） andtransmission electron microscopy （TEM） showed that the platinum nanoparticles had ahollow structure and also had a good dispersion on graphene. Methanol electrocatalyticoxidation experiments show that the the as prepared platinum hollow nanoparticlesloaded on graphene （Pt-H-G） has a better electrocatalytic properties than thecommercial carbon black supported platinum catalysts （Pt/C） in aspect of onsetpotential for MOR and mass activity.For the cathode,we used a very simple method successful synthesis of thePt/Mn₃O₄/CNTs three-layer structure composite catalyst.Potassium tetrachloroplatinatewas reduced by Mn₃O₄at a certain temperature and growth in the surface of theMn₃O₄,meanwhile Mn₃O₄nano-particles is coated on the surface of the carbonnanotubes. The carbon nanotubescan be formed a three-dimensional conductive networkto solve the problem of poor conductivity of metal oxides of Mn₃O₄.SEM and TEMshows that the as prepared Pt/Mn₃O₄/CNTs indeed of three-layer composite structure, and platinum well dispersed on the surface of Mn₃O₄.The oxygen reduction reaction testshow that its performance is superior to commercial carbon black, platinum catalyst（Pt/C）. Accelerate durable test （ADT） experiments showed that the as preparedthree-layer composite structure catalyst did not achieve the desired results,X-rayphotoelectron spectroscopy （XPS） further indicates that the reasons for the poor stabilityof this catalyst is the vector of carbon corrosion in carbon nanotubes （CNTs）.