Study Of Noble Metal Supported On External Modified Graphene

The two-dimensional graphene, which not only has the thickness as atomic scale, but also owns excellent electrical properties, and great specific area, allegro electron transfer rate,’quantum hall effect, become outstanding carrier material. The modification or functionalization of graphene can sharply change its electronic structure, improve its properties and broaden its applications. In this dissertation, based on density functional theory (DFT) calculations, taking external modified graphene as fundemental model system, we not only investigate noble metal adsorption and co-adsorption with other atoms, but also design Au-based catalyst that adsorbed on O/Au co-modified graphene and study the adsorption of C2H2and HC1.For noble metal adsorbed on pyridine alkyne modified graphene, our studies show that Pt atoms that adsorb on1,3-dipolar cycloaddition graphene induce the deprotonation of this1,3-dipolar cycloaddition graphene and then the configuration changes to adeprotonated1,3-dipolar cycloaddition graphene, and the Ptn(n=3-6) nanowire adsorption configurations are more stable than the corresponding Ptn (n=3-6) clusters adsorption configurations. An electronic structure analysis of the composite shows that the noble metal anchoring site on the deprotonated1,3-dipolar cycloaddition graphene is the ortho-carbon of nitrogen,which was further confirmed by the average Bader charge of the ortho-carbon, as high as1.0e; Pt metal adsorption does not essentially change the electronic property of deprotonated1,3-dipolar cycloaddition graphene which Pt6cluster adsorption composite is metallic while Pt6nanowire adsorption composite is semi-metallic. We also study different metal and different modified graphene, the result shows that noble metal adsorbed [2+2]PyNG-2is most stable and Pt is better than Pd. These studies are consistent with experimental reports and can provide new mechanism and idea.We further investigated O/Au co-modified graphene, design new Au-based composite catalyst and study the adsorption of C2H2and HC1. The result shows that the O/Au co-modified graphene can be used as carrier material of Au-based catalyst and the configuration of C2H2adsorbed on Au-based catalyst is much stable, which reflect the catalysis potential.