Preparation Of Graphene And Research On The Performance Of Platinum/Graphene Composite As Catalyst

Graphene is a kind of two dimensional crystal materials with one atom thickness.Carbon atoms were arranged in a honeycomb of lattice structure. This uniquestructure gives it excellent optical, mechanical, and thermal properties. Graphene hasa large surface area, can well disperse catalyst particles, and has a very stablestructure. It is excellent catalyst support for low temperature fuel cell. In this paper,we combine the low temperature thermal expansion and chemical reduction way toprepare graphene, and do a research on the change behavior of oxygen groups on thesurface of carbon materials. We also analysis the influence factors during thepreparation steps on the performance impact of the platinum/graphene.In this paper, we use an improved method to prepare the highly oxidized graphiteoxide on the basis of Hummers method.Thenthe low temperature (400oC) inflationwasapplied to remove most of the oxygen groups on the surface of graphite oxideand getexpanded graphite. To reduce more residual oxygen functional groups, microwaveheating ethylene glycol reduction method was used.We also prepared theplatinum/graphite composite materials by synchronous reduction of expandedgraphite and hexachloroplatinicacid.In the experiment, we analyzedsome influencingfactor to the structure and catalytic performance of the Pt/Gr, including the time ofmicrowave heating, the pH value of the solution, and the water content in ethyleneglycol. Electrochemical properties of Pt/Gr werecharacterized through the cyclicvoltammetry test. The surface structure of Gr and Pt/Gr were observed by thetransmission electron microscope (TEM) and scanning electron microscope(SEM).The results of the study show thatwe can get high platinum loading Pt/GrNano composite materials. The average particle size of platinum in Pt/Gr with40wt%platinum loading is about3.0to3.5nanometers. It has high catalytic activity tohydrogen and oxygen electrode reaction, and can be used as proton exchangemembrane fuel cell electric catalysts.