| 本文已被：浏览次 下载次 |
码上扫一扫！ |
|
|
|
| Epoxidation of cyclohexene on LaCoO3 perovskite oxides |
|
SHI Bin, ZHANG Bin, ZHANG Xuelong, LIU Huan, QIAN Yanghui, RUAN Xiaoyun, LI Zhongtao
|
|
(State Key Laboratory of Heavy Oil Processing in China University of Petroleum (East China), Qingdao 266580, China)
|
| Abstract: |
| The LaCoO3 perovskite composite oxides were prepared with Co(NO3)2 and La(NO3)2 under alkaline condition by coprecipitation. The oxides were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N2 adsorption-desorption. It is found that the basic particle size of LaCoO3 perovskite is 80-120 nm and the specific surface area is 9.0 m2/g. The catalytic epoxidation of cyclohexene was conducted in an autoclave with LaCoO3 perovskite, O2 as oxidant, isobutyraldehyde as catalytic auxiliary, and N,N-dimethyl formamide (DMF) as solvent. The results show that the LaCoO3 perovskite prepared by coprecipitation could achieve the highest activity under the conditions of pH=8,20 ℃ of precipitation temperature, calcination temperature of 700 ℃ and calcination time of 4 h. The best catalytic epoxidation condition is O2 pressure 4 MPa, reaction temperature 50 ℃, reaction time 5 h with catalyst mass 0.2 g and cyclohexene mass 2.0 g. The conversion of cyclohexene and the selectivity of epoxycyclohexane could reach 64.9％ and 68.6％, respectively. |
| Key words: perovskite cyclohexene catalytic oxidation molecular oxygen precipitation selectivity |
|
|