Step Synthesis Of Indole From Aniline And Ethylene Glycol Cu / Sio <sub> 2 </ Sub> Catalyst For The Study

Indole, which is an important raw organic material and fine chemical product, has many uses in the fields of industry, agriculture and medicine. Although there are some methods to produce indole, one of the most promising routes, from an industrial point of view, seems to be the synthesis from aniline and ethylene glycol. Because it is one step from reactants to indole and utilizes inexpensive starting materials, a low cost process on the industrial scale could be possible. In this dissertation, the effect of promoters on the performance of Cu/SiO2 catalyst and the preparation methods of supported copper catalyst were studied for the direct synthesis of indole.The promoters such as, alkali metal oxides, alkaline earth metal oxides and transition metals were doped into Cu/SiO2 catalyst by separate-step impregnation method and the effects of different promoters on the performance of Cu/SiO2 catalyst were investigated. The experimental results showed that MgO promoter and K2O promoter with certain amounts could obviously improve the selectivity of Cu/SiO2 catalyst. Although transition metal promoter iron couldn't increase the selectivity of indole, it could improve the stability of the catalyst. The dispersion of Cu/SiO2 catalyst prepared by ion-exchange method is good, however, its selectivity is lower than that of Cu/SiO2 catalyst prepared by impregnation method. And the catalyst Cu/SiO2 prepared by ultrasound-impregnation method couldn't greatly improve the catalytic performance. The results of TEM and XRD showed that the selectivity of Cu/SiO2 catalyst was high when copper particle size was about 33 mn and the crystallinity of copper reached definite value. Too big or too small of copper crystallinity would resulted in the more by-products and the less selectivity.