Nano Mediated Kong Amorphous Alloy Catalysts And Their Catalytic Hydrogenation Performance

The amorphous alloy is 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. Clearly, modifying the supported catalysts or making some metal catalysts with large surface area are feasible means.In stead of using the regular SiO2 support to synthesis the support catalyst, we choose the mesoporous material(MCM-41, SBA-15), having large surface area and ordered pore structure as the support to synthesis Co-B/MCM-41 and Co-B/SBA-15 amorphous alloy catalysts applying to the selective liquid phase hydrogenation of cinnamaldehyde (CMA) to cinnamyl alcohol (CMO). Then we modify 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). Above the two meanings, we synthesis the mesoporous metal Co-B amorphous alloy catalysts, bearing mesoporous structure and ordered pore channel using controlling the speed of the surfactant and the Co2+ for the first time, and then discuss it's catalytic function via the selective liquid phase hydrogenation of cinnamaldehyde (CMA) to cinnamyl alcohol (CMO). The main research conclude:1. Catalyst preparation1) Supported M-B amorphous catalyst was prepared by impregnating regular or mesoporous support with a solution containing M2+, then dried by oven, and followed by calcining and KBH4 reducing.2) Co-B amorphous alloy was prepared by adding KBH4 into a solution containing CoCl2 directly.3) Preparation of mesoporous Co-B amorphous alloy: solution containing CoCl2, EtOH, CTAB was mixed in certain temperature, followed by dropping the KBH4 until the Co2+ reduced absolutely. Then through extraction to obtain the meso Co-B.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 much higher catalytic activity and selectivity for the supported mesorpous amorphous alloy catalysts. 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 mesoporous Co-B show large surface area, mesoporous pore structure and display excellent catalytic performance.3. The catalytic performance and the structure of the catalysts1. Amorphous alloy particles supported on mesoporous materials in stead of the regular disordered supports seemed favorable for improvement of catalytic activity and selectivity Such promoting effect could be attributed to higher special surface area and ordered porous structure. And mesoporous material was also helpful for the electronic transfer.2. 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.3. The meso Co-B was obtained by controlling the speed of the surfactant and the Co2+, owing large surface area, mesporous pore structure and high dispersion of the active site which leading to the higher activity and selectivity in the reaction of CMA to CMO than the Co-B by regular reduction.