Preparation Of Platinum Supported On Activated Carbon And Synthesis Of P-chloroaniline

p-chloroaniline is used as important chemicals and intermediates for the production of many fine chemicals such as dves, herbicides, pesticides, rubber and drugs. The main route to the p-chloroaniline was through the reduction of the corresponding nitrocompounds with metal-acid systems. However, the method of reducing p-chloronitrobenzene with noble metal is now growing, due to the environmental impact. By now, the import Pt/C catalysts are extensively used because they have higher activity compared. Therefore, an extensive study concerning the preparation method of Pt/C catalyst, the deactivation of Pt/C catalyst and bimetal catalyst for the hydrogenation of p-chloronitrobenzene have been carried out.1. The wet impregnation was used to prepare Pt/C catalyst in the paper. The effect of impregnation method, impregnation solutions, loading content of Pt, reduction temperature and the carbon pre-treatment on the activity was discussed. It has been found that the catalyst prepared by excess impregnation method is more active than the other. And the impregnation solution effects Pt content on catalyst's surface. Results shows that the catalyst impregnated in acetone has a selectivity of p-chloroaniline over 93.6%, better than the catalysts impregnated in ethanol or water. It has also been found that solution concentration and reduction temperature can affect the size of Pt and the Pt distribution on surface. The condition of the solution concentration 2.7×10-3g/mL and reduction temperature 400℃is a good choice. Meanwhile, the carbon pre-treatment can improve the activity and selectivity for the hydrogenation of p-chloroaniline. When the size of carbon equals 300 mesh or exceeds, it exhibits high activity. And appreciable proportion of sulfur content can improve the selectivity remarkably.2. Further research about the Pt/C catalysts is discussed based on the above studies. Effect of the secondary metal(Co,Ni,Sn,Ce,Mo), the content of secondary metal, the loading sequence and the addition method of secondary metal are investigated. Results show that the addition of Co, Ni, Ce, Mo respectively can...