| Butenes including 1-butene and 2-butene were important chemical materials. At present, butenes were primarily produced from separating of C4 hydrocarbons. The catalytic dehydrogenation of light hydrocarbons into more valuable unsaturated hydrocarbons has become one of the challenging research subjects in the area of heterogeneous catalysis. C4 hydrocarbons had been produced abundantly in the petrochemical process in China. In order to effectively convert them especially n-butane into more valuable butenes, it was significant to study catalytic dehydrogenation of n-butane not only theoretically, but also industrially.Two kind catalysts including vanadium catalysts, chromium catalysts were investigated in this thesis. The silica gel which was more suitable for dehydrogenation of n-butane was chosen as carrier from several carriers. The catalysts were all prepared by impregnation. The results showed that the calcination temperature and loading effected on the activation of catalysts. The reaction conditions such as reaction temperature, ratio of H2 to n-C4H10, weight hourly space velocity (WHSV) and reaction time, were investigated by micro-reaction equipment under the optimal preparation conditions of catalysts. Last, it was studied that compose, configuration and other information of active species are characterized by means of XRD, UV-vis, FT-IR, Raman and BET.In chapter three, the VOx/SiO2 catalysts were studied in catalytic dehydrogenation of n-butane. The preparation conditions of catalysts and reaction conditions were investigated. The results showed that when the calcinations temperature was 550℃and VOx loading was 12 wt.%, the catalysts showed the best activation, and when the reaction conditions were reaction temperature during 590 to 600℃, the ratio of H2 to n-C4H10 during 1 to 2 and the WHSV during 2000 to 4000 ml/h/gcat, it could get better n-butane conversion, butene selectivity and butene yield. It was investigated that the configuration and surface characteristic of VOx/SiO2 catalysts were affected by calcination temperature and VOx loading via methods of XRD, UV-vis, FT-IR, BET and Raman. The tetrahedral and octahedral V5+ species were mainly existed in catalysts. The more VOx loading was added, the more octahedral V5+ specie was produced. The activation of catalysts decreased due to the BET surface area reduced at high calcinations temperature and VOx loading.In chapter four, the CrOx/SiO2 catalysts were researched in catalytic dehydrogenation of n-butane. The best preparation conditions and reaction conditions of catalysts were studied by reaction. The structure of catalysts was analyzed by means of XRD, UV-vis, FT-IR and Raman. It is showed that when the calcination temperature was 550℃and CrOx loading was 12 wt.%, and when the reaction conditions were reaction temperature during 590 to 600℃, the ratio of H2 to n-C4H10 during 1.5 to 2.5 and the n-butane WHSV during 1 to 2 h-1, it could get better n-butane conversion, butene selectivity and butene yield, i.e. the butene yield could reached 28%. The CrOx/SiO2 catalysts mostly existed Cr(Ⅵ) and Cr(Ⅲ) species. The activation of catalysts decreased which was attributed to the BET surface area reduced and CrOx loading added.In chapter five, two reaction mechanisms were studied for two catalysts respectively. The distribution of 1-butene, cis-2-butene and trans-2-butene was affected by reaction temperature mainly, and hardly influenced by preparation conditions and the other reaction conditions. The isobutene was produced about 5% selectivity over VOx/SiO2 catalysts, but nearly none over CrOx/SiO2 catalysts.
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