| Graphene is a new type of two-dimensional atomic crystal, with single carbonatomic layer in sp2hybridization, which shows excellent electrical, mechanical, thermal,optical properties and owns large specific surface area to make graphene as an idealtemplate for carrying metal nanoparticles catalyst.In this thesis, a series of graphene supported PdCu nano-catalysts were synthesized.The catalytic properties of the catalyst on reducing nitrobenzenes to anilines wereinvestigated, the main content and results are as follows:(1) Graphene oxide was prepared by improved Hummers’ method. Graphene supportedPdCu nano-catalysts were synthesized by reducing graphene oxide and metalprecursors with reducing agent hydrazine hydrate and ethylene glycol. The resultsindicated that compared to hydrazine hydrate, ethylene glycol on the reduction ofgraphene oxide and the formation of metal alloy had a better effect.(2) Graphene supported different ratios of PdCu nano-catalyst (Pd:Cu molar ratio of1:1，1:2，2:1) were prepared by ethylene glycol as a reducing agent. Graphenesupported Pd and graphene supported Cu also were synthesized as a comparison.The catalysts were characterized through X-ray diffraction (XRD), X-rayphotoelectron spectroscopy (XPS) and transmission electron microscope (TEM).(3) Reduction of nitrobenzene to aniline was selected as a model reaction. Weinvestigated the effect of catalysts, reducing agents, solvents, reaction temperatureon reduction of nitrobenzene and found the optimized reaction system for aromaticnitro reduction. With the optimized reaction system, several nitrobenzenes werereduced. The result showed the catalyst exhibited a good activity on nitrobenzenephenolic compounds, alcohol, nitrile, ester, amide, sulfonamide and halogen nitrocompounds.(4) PdCu/G catalyst after reaction was collected and applied in the reduction reactionof nitrobenzene. After six cycles, the catalyst still maintains a good activity (93%yield). Morphology of the catalyst was characterized. |
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