Role Of Rare Earth Additives And Iron Additives Step Synthesis Of Indole-aniline And Ethylene Glycol Ag / SiO <sub> 2 </ Sub>-ZnO Catalyst

Indole, which is an important raw organic material and fine chemical product, has many uses in the fields of industry, agriculture and medicine. There are many methods to produce indole. However, from an industrial point of view, the direct synthesis from aniline and ethylene glycol seems to be one of the most promising routes. 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, silver catalyst was investigated for the direct synthesis of indole. The effects of rare earth promoters and iron promoter on the performance of Ag/SiO2-ZnO catalyst are mainly studied.The rare earth oxides promoters such as CeO2 ,La2O3 and transition metal promoter FeOx were doped into Ag/SiO2-ZnO catalyst by separate-step impregnation method and the effects of different promoters on the performance of Ag/SiO2-ZnO catalyst were investigated. The experimental results showed that the promoters of CeO2, La2O3 or FeOx with certain amounts could obviously improve the performance of Ag/SiO2-ZnO-ReO-FeOx catalyst. And the loading sequence of active component and promoters could also affect the activity and stability of the catalyst. TPR profiles indicate that doping CeO2 or FeOx into Ag-group catalyst supported over silica could lower the reducing temperature of Ag2O and make Ag2O reduce easily. Doping La2O3 could increase the reducing temperature of Ag2O and make Ag2O reduce uneasily. The promoters of CeO2 and FeOx may be electron-promoters.