Pd In Graphene Based Materials And Their Electric Catalytic Properties Research On Load

Low-temperature fuel cells have been considered as a green and high-efficient device abased on energy transformation. The low efficiency and high cost of noble metal catalyst, however, hamper the development and further commercialization of fuel cells. Hence, how to well reduce the usage and improve the catalytic performance of noble metal is very significant for the practical application of fuel cells. On the basis of the above consideration, we have developed series of the effective strategy for the fabrication of small-sized and high-dispersed Pd nanoparticles on graphene and WC/graphene, which further enhance the catalytic performance of metal noble and exhibit potential applied importance in the fuel cells.Based on the stability of the abundant oxygen-containing groups on the graphene oxide for Pd nanoparticles, the controllable synthesis of small-sized and high-dispersed Pd nanoparticles was achieved on graphene through separated step chemical reduction. Series of experiments showed that the oxygenated groups played important role in the stabilization of Pd nanoparticles. Moreover, the morphology and performance of the catalysts with different Pd content were investigated in depth, and the results indicated that the Pd content of catalysts effected directly on the size and dispersion of Pd nanoparticles on graphene and its catalytic performance for formic acid oxidation.Utilizing the reducing ability of graphene for Pd2-ions, Pd nanoparticles were in situ formed on the surface of graphene. After introducing formic acid, Pd nanoparticles were etched to Pd2+ions under atmosphere. Meanwhile, these Pd2+ions were also reduced as small-sized Pd nanoparticles by formic acid. Through deep investigating the formation mechanism of small-sized Pd nanoparticles on graphene, it was concluded that the size and dispersion of Pd nanoparticles were affected by the cooperation of oxygen etching and reduction using formic acid. In addition, it was also investigated that Pd/graphene catalyst was applied in electrocatalytic oxidation of formic acid.The WC/GN composite was successfully synthesized through hydrothermal method followed by high-temperature annealing, and the formation mechanism of WC on graphene was further investigated and discussed. The WC/GN composite was used as excellent catalytic support for depositing Pd nanoparticles. The researches showed that Pd nanoparticles were tightly contacted with WC nanoparticles on graphene, and the strong electron interaction existed between them, which generate high-efficient synergistic effect for ethanol oxidation and significantly enhance the catalytic performance.