Studies On The Synthesis Of New Ni-Based Nanocomposites And Its Catalytic Properities

Metal nanoparticles have broad application prospects in adsorption separation, biomedical, catalytic electrode materials, and other fields. Its performance strongly depends on the metal particle size and its dispersion. Therefore, the preparation of high stability,uniform size and regulation of metal nanoparticles has vital significance.In the thesis, Ni/C、 Ni-Al2O3C nanomaterrials can be obtained through in situ self-reduction of layered nanocomposites intercalated with salicylates. The composition, structure and particle size of prducts can be controlled by the changing the chemical composition and preparation conditions of precursor. And we studied the magnetic and catalytic properties of product. The concrete research content is as follows:1. The rod-like Ni/carbon can be obtained through in situ self-reduction of one-dimensional (1D) uniform layered Nickel hydroxides precursors, which using salicylates as bridging ligands have been synthesized in water under mild conditions in a simple process. As is well known for us nickel has been found to be effective transition metal catalyst for catalytic hydrogenation Therefore, here we choose hydrogenation of chloronitrobenzenes (CNB) to make the corresponding chloroanilines (CAN) as a probe reaction to investigate the activity and stability of Ni/C catalysts. And the Ni/carbon composite obtained at600℃exhibites high performance in activity and selectivity for the hydrogenation of chloronitrobenzene(CNB). In addition, the encapsulated Ni nanoparticles by carbon gives rise to a high stability.2. Herein we present a facile and scable strategy prepare the novel three-dimensional(3D) flower Ni-Al2O3C catalysts nanostructures and the nickel loading of the Ni-Al2O3/C can be controlled by adjusting the mole ratio of Ni2+and Al3+. The three-dimensional flower Ni-Al2O3/C can be obtained through in situ self-reduction of three-dimensional flower uniform Ni-Al layered double hydroxides precursors, which using salicylates as bridging ligands have been synthesized in water under mild conditions in a simple process. The Ni-Al2O3/C composite exhibites high performance in activity for the liquid-phase reduction of4-nitrophenol (4-NP) by NaBH4. In addition, the encapsulated Ni nanoparticles by carbon gives rise to a high stability without oxidation/sintering/aggregation of active species during long-term use and the magnetic of Ni core provided a convenient route for separating the catalyst from the solution.