Synthesis Of Functionalized Graphite Oxide-supported Pd Nanoparticles And Properties In The Catalysis

Graphite oxide, a kind of new carbon materials with excellent properties, is usually treated as a precursor to synthesize graphene. Because of its high specific surface area and the oxygen containing functional groups(hydroxyl, carboxyl), graphite oxide is used widely to prepare different kinds of heterogeneous catalysts. In the paper, we obtained the catalysts by modifying the surface of graphite oxide with various silane coupling agents, and studied the catalytic properties. It has two parts of main research contents:The first part, graphite oxide performed as the carrier, then treated by 3-mercaptopropyltriethoxysilane(MPTES), and followed anchoring the palladium with mercapto group to get the catalyst(GO-SH-Pd). The catalyst was characterized by FT-IR?XRD?TEM?TGA?Raman and elemental analysis, then we chose the hydrogenation of phenylacetylene as a probe reaction to study the catalytic properties of GO-SH-Pd. The experiment results indicated that the catalyst was active for hydrogenation of phenylacetylene with a good selectivity of styrene; when the reaction was carried out at 40 ? and 1atm H2 for 2h, the conversion of phenylacetylene can be reached to 93.8%, and the selectivity of styrene can be reached to 92.1%; after reacting another 2h, the conversion of phenylacetylene was obtained at 98.5% with the selectivity of styrene at 91.4%. It showed that, according to the reaction, the selectivity of styrene remained unchanged; at the same time, the GO-SH-Pd catalyst can be used ten times without evident reduction of catalytic activity and styrene selectivity.The second part: the GO-NN-Pd catalyst was prepared by immobilizing Pd nanoparticles on graphite oxide functioned with 3-(2-aminoethyl)-amino propyltrim-ethoxysilane, then characterized by XRD?FT-IR?TEM and TGA. The catalyst showed a excellent catalytic activity in Heck coupling reaction, and was applicable to a wide range of substrates(when we used the olefin contained the phenyl and acrylate as substrates, we can get morn than 99% yield; and we can obtained 80% yield when we used straight chain olefins). After reused four times,the product yield was still kept at 99%.