Due to the selective catalytic reduction(SCR)activities of Mn at low temperature and the oxygen storage capacity of Ce,Mn and Ce were introduced into V-W/Ti. Eight catalyst samples were prepared by the impregnation method. The experiments of deNOxand resistance to H2O and SO2for the catalysts were conducted with ammonia gas as the reductant in a fixed-bed stainless steel reactor. The properties of different catalysts were characterized by NH3-TPD,H2-TPR,N2-physisorption,and XRD. The 3V-10W-7.7Mn-4.3Ce/75Ti catalyst sample showed satisfactory performance at 240℃ with NO removal efficiency>95% at 180—330℃ and 80% remaining in H2O and SO2at 240℃. It possesses substantial strong acid sites that enhances the adsorption capacity for NH3due to the 7.7% MnO2,and moderate Ce also promotes its low-temperature redox capacity. MnO2and CeO2can highly be dispersed on the surface of TiO2although the BET surface area of 3V-10W-7.7Mn-4.3Ce/75Ti is close to 67m2/g.%结合Mn的低温脱硝活性与Ce的储氧能力,将Mn-Ce作为整体改性剂,添加到传统钒钨钛催化剂中,用浸渍法制备了8份样品,以 NH3为还原剂,于管式固定反应器内进行脱硝及抗水抗硫实验,通过 NH3-TPD、H2-TPR、N2物理吸附测试、XRD手段对样品进行表征.综合脱硝活性及240℃抗水抗硫测试结果,选出较优的改性催化剂为3V-10W-7.7Mn-4.3Ce/75Ti,其在180~330℃保持脱硝活性95%以上,240℃抗水抗硫活性稳定在80%左右.该样品的比表面积虽然不到67m2/g,但是MnO2与CeO2高度分散在TiO2表面;7.7%含量的MnO2也使催化剂具有大量的强酸位点,能够增强对NH3的吸附;适当含量的Ce也增强了催化剂的低温氧化还原能力.
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