| The preparation of catalyst for C3 olefin atnmoxidation from sepiolite and pure BiQ3 being produced from bismuth concentrate with the chlorination- distillation process was studied as well as mechanism of activation adsorption of NH3 on the catalyst surface. The processing conditions of acid modification, such as temperature, ratio of solid to liquid, acidity and treatment time, were studied by the orthogonal method, and then the method supported activation components and calcination conditions were studied too. Experimental results show that the catalyst with distribution uniformly of activation components was obtained at point of 0.1 MPa drive pressure by impinging stream method. Especially, the conditions of removing Cl" were investigated in detail for preparation carried out in the salt chloride system and determined the rate of Cl" removing by concentration of CO^2' ion in solution. 20ppm of remainder of Cl" was found on the catalyst surface washed by a secondary distilled water solution of 0.25mol -1/1 (NH4)2CO3 .Three catalysts formula were obtained by the uniform design and stepwise regression methods. The conversion of propylene is more than 98%, and selectivity to acrylonitrile more than 81%, when feed gas composition is 7.7% of propylene, 8.05%:of NH3, 84.3% of air, space velocity(GHSV) is 3000cm3 -g"1 -h"1, and temperature is 530"C. Further the 78.2% of propane conversion and 60.6% selectivity to acrylonitrile were reached after the catalysts by uniform design were applied to propane ammoxidation at the conditions that V(propane):V(NH3):V(O2)=l: 1.2:5, GHSV=3000cm3 ?g*1 ?If1, temperature 55VC.Catalytic activity rating of sepiolite-supported catalyst in the salt chloride systems was carried out in self-made fixed bed reactor. The effects of Chloride content, temperature, distribution of porous of catalyst, support and space velocity (GHSV) of the feed gas on catalytic activity were detected. The results showed mat sepiolite supported catalysts have good performance for propylene ammoxidation since Cl%< 0.004% and the catalytic activity was lost after Cl%>0.04%. Supporters of catalyst had effect on catalytic activity markedly and its activity decreased with the different carrier in the following order: sepiolite玸ilica geb-alumina. 98.5% of propylene conversion was obtained and 81.7% selectivity of acrylonitrile at the conditions that V(propylene):V(NH3):V(air)=l:1.05:ll, GHSV=3000cm3 ?g'1 ?h'1, temperature 530X: and 40nm~-100nm porous distribution of catalystXRD, EPMA, TPD, BET were used to characterized the multicomponent Bi-containing catalyst. The XRD results show that Bi is existed in 3 -bismuth molybdates, and Ni, Fe, Coin molybdates salts accordingly. But the tautozonal metalepsis is presented in catalyst while low content of Ni is existed in catalyst. The uniformly distribution of activation components were detected by EMPA when sepiolite-support catalysts were prepared by impinging stream process, and big pore and suitable specific surface area were detected by BET, ranging from 80nm~100nm. Two acid centers on the sepiolite-supported catalyst were characterized by TPD, which the point of temperature of NH3 dessorption were 430 "C and 540 "C respectively, but the only one acid center was detected on the catalyst supported by silica.Ab initio including correlation energy have been employed to optimize the geometry of NHs adsorption on surface of bismuth molybdates, activation character and effects of Cl", support on activity of catalyst as well. L-center and B-center configurations were presented in multicompontent catalyst after calculation was carried out, and the L-center configuration is more stable than B-configuration. NHa was adsorpted on the Mo site of the surface and been activated, which the electron transfer from HOMO of NHs to LUMO of catalyst bulk. The energy gap between them is 0.5 a.u. The energy of LUMO of catalyst was increased, and the gap was increased accordingly when Cl" was existed in catalyst, which NHs was difficult to activation adsorption. Opposite...
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