Preparation Of Ag Carbon Nanofiber Composite Nanocatalyst And Their Performance For Styrene Oxidation

Nanotechnology has been widely concerned with the development of science and technology. The achievements that the studying of the nanoparticle catalyst highlight the superiority of the nanoparticle catalyst. Nanoparticles catalyst was used as supported metal catalysts,catalyst carrier material has played an important role on the reactive activity of nanoparticles.Therefore, the topic that looking for and preparing for the catalyst carrier with special properties was a hot topics in catalysis. Carbon nanofiber Nanomaterial is a kind of catalyst support material, it overcomes the disadvantages, such as the catalysis is difficult to recycle, the recycle is poor and the nanoparticle is reunion.The article made the carbon nanofiber with Ag nanoparticle by electrospinning technology, chemical reduction and high temperature carbonization technology, the carbon nanofiber was applied in the reaction of styrene epoxidation and proved the catalyst performance.The main content and results as follows:Firstly, the porous carbon nanofiber was prepared by two kinds of methods. The first method:the PAN nanofiber films was prepared by electrospinning, the nanofiber films were smoked by Br2 and the AgBr was removed by Na2S2O3 coordinated, the porous carbon nanofibers were formed by high temperature carbonization. The influence that the smoking day impacted on carbon nanofiber morphology was investigated and the best day was 4 days. The second method explored the PMMA/PAN nanofiber films were calcined,the PMMA was decomposed in high temperature and the porous that had formed. The best proportion was 10 by characterization of SEM and TEM.Secondly, it based on the porous carbon nanofibers were got by the pyrolysis remove polymer and combined the research of the method that inorganic/organic composite nanofibers, the AgNO3 were added into the solution of PMMA/PAN, AgNO3-PMMA/PAN nanofiber films were got by electrospinning and the porous carbon nanofiber with Ag nanoparticles was got by high temperature carbonization. The best proportion of PAN/PMMA/AgNO3 was 10/1/1 by experimental parameter control. It had studied the performance that catalytic styrene epoxidation reaction. The result showed that the best solvent was acetonitrile, the best oxidant was tertiary butyl peroxide, the best reaction time was 24 h, the conversion of styrene reached 71.2 % and selectivity of the styrene oxide of 83.2 %.The catalyst had good catalytic activity after recycling 5 times.Finally, on the basis of Ag carbon nanofiber, the copper resource was introduced the Ag carbon nanofiber and bimetallic carbon nanofiber catalyst was got,The catalyst performance was affected by the amount of doped copper. The Cu(NO3)2 was added into the solution of PAN/AgNPs and the activity of catalyst was studied by the reaction of styrene oxidation. The result showed the conversion of styrene was improved due to the copper was added. The conversion of styrene improved from 66.4 % to 99.0 % when the amount of Ag and Cu were the same. Meanwhile the Cu affected the main products and improved the content of the benzaldehyde. The selective of styrene oxide was 41.9 % and the selective of benzaldehyde was 40.6 %.In a word, the catalyst with Ag nanoparticle provided a new way to prepare the catalyst. The catalyst achieved the goal that simple and green.It has application value and far-reaching practical significance in improving the catalytic efficiency.