Design Of Precious Metal-modified Ggraphene And The Application In Epoxidation Of Styrene

Graphene is a new carbon material which is tightly packed into a singletwo-dimensional honeycomb lattice structure by sp2hybridizated carbon atoms.It not onlyhas the extremely good crystallinity and mechanical properties and electrical quality,butalso has high theoretical specific surface area,thermal conductivity and mechanicalproperties and outstanding high electron mobility at room temperature.And that is suitablefor developmenting high performance composite materials.Disperses inorganic materialsonto the surface of graphene films to made graphene/inorganic nanocomposites.Modifiedby inorganic nanoparticles can prevent the graphene layers together,and maintain theirinherent characteristics of graphene and inorganic nanoparticles,but also producing novelsynergistic effect,which has extensive application value.In this paper, we use chemicaldepositing method and intercalating method to decorate inorganic nanoparticles onto thesurface of graphene, in order to prepare new graphene composites, and apply to theepoxidation of styrene reaction.The main research content is as follows:1.Synthesis,characterization,and photocatalytic activity of Ag-RGO compound inepoxidation of styrene.In this work，we use natural flake graphite and silver nitrate as rawmaterial, sodium borohydride (NaBH4) as the reducing agent, hexadecyl trimethylammonium bromide (CTAB) as dispersant.We use improved Hummers method to preparedgraphene oxide, and silver nanoparticles was loaded on the surface of graphene bychemical depositing method,finally a series of Ag-RGO composite catalyst wereprepared.Using XRD, FT-IR, SEM and TEM to characterize the catalysts.We discussedthe influence of reaction time,the dosage of catalyst,H2O2/Styrene mole ratio,the dosageof hydrochloric acid,the mass fraction of metal in epoxidation of styrene.The resultsshowed that,with acetone as solvent, H2O2as oxidant, the mass fraction of silver is5%，namely5%Ag-RGO has the best catalytic effect on styrene epoxidation experiment.Theconversion rate of the epoxidation of styrene system can reach19.8%, the selectivity ofepoxy ethyl benzene is56.96%.2.Synthesis,characterization,and photocatalytic activity of Ag-RGO nanocomposites in epoxidation of styrene.We use natural flake graphite as raw material,and improvedHummers method to prepared graphene oxide.Using AuCl3·HCl·4H2O as goldsources,sodium borohydride (NaBH4) as the reducing agent, hexadecyl trimethylammonium bromide (CTAB) as dispersant,and loading gold nanoparticles on the surface ofgraphene by chemical depositing method,in order to get a series of Au-RGO compositecatalyst. Using XRD, FT-IR, SEM and TEM to characterize the catalysts.With acetone assolvent, H2O2as oxidant,3%Au-RGO composite as catalyst to catalysts the epoxidation ofstyrene, the conversion rate can reach19.8%, the selectivity of epoxy ethyl benzene is56.96%.3.Synthesis,characterization,and photocatalytic activity of GO/Ti-SBA-15catalyst inepoxidation of styrene reaction.We use P123as template agent,tetraethyl orthosilicate asraw material to synthesis SBA-15through the hydrothermal method.Using graphene oxideas the carrier which was prepared by improved Hummers method,then SBA-15modified bytitanium was inserted into the graphene oxide layers.By means of XRD, SEM, IR andUV-Vis characterization methods to characterize the structures of GO/Ti-SBA-15compounds.With acetone as solvent, H2O2as oxidant, by the selection of solvent, changingthe dosage of the catalyst and the molar ratio of H2O2/Styrene etc, finally determine thebest conditions of50%GO/Ti-SBA-15for the reaction of epoxidation of Styrene, and themaximum conversion rate is26.13%，the selectivity of epoxy ethyl benzene is61.06%.