The Controllable Synthesis Of Palladium-based Nanomaterials And Their Catalytic Properties For Small Molecular

As the foundation of the nano-science and nano-technology which has aroused the world’s attention increasingly, the development of the nanomaterials becomes one of the leading fields of the international science research. The paper summarizes the latest classification of nanomaterials, the latest preparation methods and their applications in new field. Based on the analysis of the above content and the expectation of environmental friendly, economical, energy saving, the paper chooses Pd-based nanomaterials as the main research content to explore the influence of the solvents, non-noble metals and oxide support on the synthesis, loading and performance of the Pd-based nanomaterials. The paper carried out mainly the following sections:Firstly, effect on the synthesis and catalytic properties of Pd/XC-72 from the different hydroxyl alcohols. Through the aqueous chemical method, three different Pd/C nanomaterials(Pd/XC-72(EA),Pd/XC-72(EG) and Pd/XC-72(GI))were successfully synthesized by a one-step solvothermal method.In the synthesis, ethanol, ethylene glycol and glycerin were used as the solvent respectively, economical XC-72 was used as the carrier, a small amount of glutamic acid was used as the addictive and palladium chloride was used as the active metal source. Then we tested their catalytic activites of the three catalysts by phemethylol oxidation. The results showed that Pd/XC-72(GI) catalyst has the best catalytic activity than Pd/XC-72(EG) and Pd/XC-72(EA).The analyzed results of XRD, TEM, FT-IR, BET and ICP-MS showed that because of glycerin, Pd/XC-72(GI) owns higher metal loadings,better dispersion and smaller size than that of the other two catalysts.Secondly, research on synthesis of Pd Cu/ XC-72 and their catalytic properties for CO oxidation. The experiment still took the carbon particles as the carrier and the solvothermal method as a way to synthesize a series of Pd Cu/XC-72 catalysts of different proportions, and we got the Pd/XC-72 and Cu/XC-72 by the same way. All the samples were dried by freezedrying method which is different with the thermal vacuum drying model. At last, we got all the Pd Cu/XC-72 samples which were loose without condensation of metal dispersion and have even particle size and good dispersion. The results of the physical and chemical properties showed that all samples contained Pd have excellent catalytic activities for the CO oxidation,and the Pd/XC-72 catalyst showed the best activity because of its high metal loadings. But take all factors in consideration, the catalyst of the Pd/Cu ratio of 1:3 performed as the optimum catalyst. Research results also showed that the addition of Cu changes the structure of Pd face-centered cubic structure, which may improve the catalytic active sites, dispersion and loadings of Pd. And correspondingly the presence of Pd also contributes to the reduction and loadings of Cu.Thirdly, synthesis of Pd Cu/flower-Ni O(Pd Cu/F-Ni O) and their catalytic properties for CO oxidation.Using CTAC as the structure oriented agents and Ni2+ as the central metal ion, we synthesized flower-like Ni(OH)2·x H2 O, which was monodispersed and nine-nanometers-thickness nanoflake assembled at a low temperature. The flower Ni(OH)2·x H2 O precursor was calcined in air at 400℃ for two hours and the structure-stable flower-Ni O was obtained. XRD, TEM and so on, showed that the F-Ni O belongs to rhombic hexahedral crystal system, and the beautiful structure is made of rough surface with holes of about nine-nanometers-thickness crisscross nano-flake. the Pd Cu/F-Ni O catalyst was prepared with the monodisperse flower Ni O as the carrier, and the catalyst showed good catalytic properties for CO oxidation at room temperature.