Study On The Structure Design And Properties Of Fiber Supported Nickel-based Catalyst

With the rapid development of industry,water pollution is becoming more and more serious.It is of great significance for the efficient degradation of organic pollutants,including aromatic nitro-compounds.Catalytic hydrogenation is a more effectively method in the degradation of organic pollutants.Nickel based materials is a common catalyst for reduction p-nitrophenol hydrogenation,has become a research hotspot.Supported nickel-based catalyst compared with non supported catalyst has the advantages of easy separation and high activity.Excellent carrier material structure can enhance the catalytic performance of nickel-based catalysts.PVA-co-PE nanofiber membrane material with high specific surface area and sisal fibers of a natural structure as carrier template were used in this paper.The fiber can be modified by physical and chemical methods and can be used to support catalyst.The relationship between the structure the properties of the material summarized,as follows:In this study nano fiber and sisal fibers were used as the supporter for catalyst active component.With the help of synthesis technology can we synthesis nickle phosphorus amorphous alloy on the surface of PVA-co-PE nanofibers.This catalyst had high catalytic activity and a membrane catalyst Ni-P/ NFM4.55 which shown the highest catalytic ability in p-nitrophenol hydrogenation reduction.The reaction rate constants were 18.04 ×10^-3s^-1 and 26wt% × 10^-3s^-1,19.04 ×10^-3s^-1,respectively,when the loading amount of Ni-P was 50wt%,25wt% and 14wt%,respectively.After the 6 run times of the catalyst,the conversion rate of pnitrophenol was still as high as 98%.The reason why the catalytic membrane had efficient catalytic rate was various,the catalyst active component was amorphous alloy.The structure of the fiber surface induced the formation of a large number of unsaturated sites and defects of the catalyst resulted to high catalytic activity,the pore structure of NFM greatly increased the probability of contact between catalyst and reactant.P doping improved the oxidation resistance of the catalyst and the adsorption capacity of p-NP.Three-dimensional network structure could also improve the catalytic activity of the catalyst.On the basis of single nickel phosphorus catalyst active component,we successfully prepared the Au/Ni-P/NFM catalytic film through support extra catalyst points.Interaction of amorphous alloy nanoparticles Ni-P and gold nanoparticles made the catalyst better catalytic ability,which was twice more than a single catalytic membrane,which shown the existence of the synergistic effect between Ni-P amorphous alloy and gold nanoparticles.The complex micro morphology of sisal fiber provides a large number of adsorption sites for nano catalyst.Mercerization treatment is one of the most effective way to change the fiber surface morphology.Mercerization treatment conditions have different effects on the morphology of sisal fiber.The micro convex structure of nano nickel film supported on the treated fiber surface was more complicated.This is the main difference between untreated fiber and treated fiber by mercerization.It can be found that the surface morphology of nanoparticle on fiber can not only copy the morphology but also has good catalytic activity.Nickel nanopartcles could be loading on the surface of sisal fiber by electroless plating method.Meanwhile the effect of loading on the catalyst activity was studied.When the load was 3.39wt%,the catalyst had the best catalytic activity that the apparent rate constant was 16×10^-3s^-1,and the TOF value reached 11.2×10^-3mol/mol/s when the load was 0.68wt%.This result can helpful to improve service efficiency of catalyst and reduce the cost as well.