Of Ceo <sub> 2 </ Sub>, The La <sub> 2 </ Sub> The O <sub> 3 </ Sub> And Of Feo <sub> X </ Sub> Additives On The Silver Catalyst Step Synthesis Of Indole's Role Research,

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. In this dissertation, silver-based catalyst was studied for the direct synthesis of indole. The effects of rare earth promoters and iron promoter on the performance of Ag/SiO₂-ZnO catalyst were mainly investigated by means of some characterizations such as XRD,TEM,H₂-TPR,XPS and NH₃-TPD.CeO₂, La₂O₃ or FeO_x promoter was doped into Ag/SiO₂-ZnO catalyst by separate-step impregnation method. The experimental results showed that the promoters of CeO₂, La₂O₃ or FeO_x with certain amounts could obviously improve the performance of the catalyst. The characterizations indicated that doping CeO₂ or FeO_x into Ag-based catalyst could lower the reducing temperature of Ag₂O and make Ag₂O reduce easily. The promoters of CeO₂ and FeO_x may be electron-promoters. The promoter of La₂O₃ with certain amounts could efficiently enhance the dispersion of silver on the silica surface and inhibit the sintering of silver during the reaction. La₂O₃ may be a structure promoter. The acidity and amount of acid of the catalyst did't change remarkably doped with CeO₂ or La₂O₃ into Ag/SiO₂-ZnO and doped with FeO_x into Ag/SiO₂-ZnO-REO.