| The oxidization of NO is the key of removal sulfur and nitration simultaneously using ammonia. The article studied on the selective catalytic oxidation of NO, aim at the weak point of selective catalytic oxidation studies. Ce-doped catalyst was supposed to improve the activity performance of catalysts. A series of experiments on the preparation and performance of Ce-doped MnOx/Ti02 and the activity performance of catalysts at different condition were studied. The oxidation of kinetic was also studied in the relevant experiment. The catalyst was squeezed at the optimum condition and amplified in the experiment for further research. The characteristic and activity performance of squeezed catalysts were studied in the initial level, which would offer reference value of this kind of technology in the industrial application.Firstly, the prepared catalysts were conducted the activity performance test in the fixed bed reactor of catalysis.The XRD, BET, SEM, H2-TPR, TG-DTA, Raman, PL, EPR, XPS and FT-IR were used to characterized the catalysts to optimize the optimum preparation condition. The effect of Ce-doped catalyst on the structure, surface properties and the activity performance were studied. The results showed that the Ce-doped was beneficial to the disperse of active component and promote the interaction of active component and support. The Ce was doped in the TiO2 lattice and caused the electronic imbalance. The oxygen vacant was occurred due to the process of balancing the electric power and the content of superoxide radical (O2-) was increased. The affinity of catalyst to oxygen was promoted. The oxygen concentration of the catalyst surface and the content of Mn3+ and Ti3+ were increased and the flux of lattice oxygen was improved. At the condition that the [Ce]/[Mn] equaled 1/3 and the loading amount was 10% with the calcinations temperature 300℃, the oxidizing ratio of NO reached 85% at the reaction condition of 250℃, space velocity of 41,000 h-1 and the concentration of NO of 400 mg·m-3.The technological condition of Ce(1)Mn(3)Ti oxidizing NO and the performance of sulfur and water resistance were studied. The results showed that the activity performance was improved at the suitable temperature, low space velocity, increased oxygen content and the reduction of NO concentration. When the reaction temperature was higher than 250℃, the catalyst has a better performance of water resistance. At the same time, the performance of sulfur resistance was increased due to dope the Ce.Moreover, the oxidization of kinetic of Ce(1)Mn(3)Ti was calculated. The results showed that the Ce-doped catalyst was efficient to reduce the activation energy and the catalyst had a good catalytic performance at a lower reaction temperature. The reaction order relevant to concentration of NO was 0.6 and the reaction order relevant to content of oxygen was 0.9. The activation energy of reaction was 21.75 kJ. The internal diffusion had much more effect on the catalyst performance and the external diffusion could be neglected.At last, the catalyst was squeezed at the optimum preparation condition into a honeycombed catalyst of 75 mm×75 mm×800 mm. The pilot test was conducted in the burner of 70 kW and the characterized of the catalysts wrer studied. The result showed that the conversion ratio of NO of 15% at the reaction condition of 270℃, space velocity of 3,000 h-1, NO 800 mg·m-3, SO2 2000 mg·m-3. Gas component and forming method effect the activity of catalyst. The content of superoxide radical was decreased when the catalyst was squeezed, and had the hing temperature of re-dox reaction. Leading to the catalyst has unsatisfactory activity. |
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