Special Morphology Of The Amorphous Alloy Materials Preparation And Catalytic Activity Of Research

Catalyst is an important material which is able to improve the rate of chemical reaction and doesn't minimize the weight of itself in the course of reaction. It plays an important part in chemical industry and the preparation of nanoparticle currently.In particular, the catalysts in size of nanometer take possession of the lack of coordinated atoms and high surface energy ,which make it easy to react to other atoms.The amorphous alloy is the range of nanometer in size and belongs to the catalyst of nanometer, a kind of material with short-range ordering while long-range disordering structure. Its unique structural character results in the excellent catalytic properties, such as the high catalytic activity and selectivity, the high resistance to the sulfur poison, especially the less environmental pollution occurred during the catalyst preparation, which is of special significance for the development trend of current chemical engineering. But so far, the amorphous alloy catalysts also have some shortcomings, such as small surface area, low dispersion of the metal and low active site of the supported catalysts. In stead of using the regular SiO2 support to synthesis the support catalyst, we choose the mesoporous material SBA-15 with the different functionalized group(CH3, NH2) to synthesis the functionalized supported amorphous alloy catalysts and apply to the hydrogenation of p-chlornitrobenzene(p-CNB) to p-chloraniline(p-CAN). Ni-B nanospheres were synthesized through chemical reduction of nickle ions with borohydride in an emulsion system comprisd of cyclohexylamine, polyethylene glycol, and water. And also apply to the hydrogenation of p-chlornitrobenzene(p-CNB) to p-chloraniline(p-CAN). We synthesis of hollow spheres with a double-shelled complex structure by using commercial polystyrene hollow spheres as templates. We synthesis the amorphous nanoparticle by spray reduction that can control the size of nanoparticle. The main research conclude:1. Catalyst preparation(1) The amorphous nanoparticle was prepared by control the reaction zone temperature, mole fractions of Ni2+, and KBH4 as key process variables for the control of particle size and size distribution.(2) Supported Ni-B amorphous catalyst was prepared by impregnating mesoporous support with a solution containing Ni2+, then dried by microwave , and followed by KBH4 reducing.(3) The hollow Ni-B amorphous catalyst was prepared by chemical reduction of nickle ions with borohydride in an emulsion system comprised of cyclohexylamine, polyethylene glycol, and water.(4) The hollow spheres with a double-shelled complex structure catalyst was prepared by impregnating Freeze-dried sulfonated templateswith a solution containing Ni2+, This mixture was treated under ultrasonic radiation and then stirring for 24h. Centrifugation,Freeze-dried,At last the former was reduced by adding KBH4 . Then the polymer was dissolved with THF under ultrasonic.2. Activity test.The liquid hydrogenation was carried out in an autoclave containing certain amount of catalyst, solvent ethanol and reagent at 1.0 MPa of hydrogen pressure and certain temperature. The activity was measured by monitoring the drop of the hydrogen pressure. The reagent conversion and the selectivity of production were obtained from product analysis by using gas chromatograph. The results showed that the functionalized supported mesorpous Ni-B amorphous alloy catalysts could favor the activity, selectivity and stronger resistance to dehalogenation in the reaction of p-CNB to p-CAN. And the hollow Ni-B show large surface area display excellent catalytic performance. The hollow Pd-B with a double-shelled complex structure apply to the reaction of Sonogashira alsodisplay excellent catalytic performance.3.The catalytic performance and the structure of the catalysts(1) Amorphous alloy particles supported on the functionalized mesoporous materials could further improve the activity, selectivity and dehalogenation of p-CNB to p-CAN, attributing to the uniform dispersion of the active site of the functionalized mesoporous materials which could favor the surface reaction of the reagent and the hydrophobic of surfaceis avail of the selectivity of the p-CAN in that the hydrophobicity of p-CAN is lower than that of p-CNB, which could inhibit the further dehalogenation reaction.(2) The hollow Ni-B amorphous alloys via microemulsion and exhibited superior activity and selectivity than regular Ni-B amorphous alloys during liquid-phase CNB hydrogenation to CAN. The main reason lied to hollow structure that could acquire much larger surface area and make nanoparticle more dispersible.