Fe-V/TiO_2催化剂NH_3选择性催化还原柴油车尾气NO_x

Fe-V /TiO_2 catalysts for selective catalytic reduction of NO_x with NH_3 in diesel exhaust

采用浸渍法制备了一系列不同Fe/V比例的Fe-V/TiO2催化剂,考察了催化剂在模拟柴油车尾气中催化还原NOx 的催化性能,采用TG、XRD、H2-TPR、NH3-TPD和Raman光谱对催化剂进行了表征。结果表明,当Fe引入后,能显著降低V2 O5在高温下的挥发,减轻了钒系催化剂在移动源的生物毒性危害。其中,Fe/V比为1：1（Fe1-V1/TiO2）的催化剂形成了FeVO4活性中心,表现出最好的催化活性,在220-420℃ NOx 转化率可达到90%以上。此外,Fe1-V1/TiO2催化剂高温热稳定性较好,并且具有较强的抗硫性能。

Fe-V/TiO2 catalysts with different Fe/V molar ratio were prepared by impregnation method. The catalytic activity of selective catalytic reaction （ SCR ） were evaluated at the simulation of diesel exhaust environment. The samples were characterized by thermogravimetric analysis, X-ray diffraction, H2 temperature programmed reduction, NH3 temperature-programmed desorption and Raman spectra. It was found that the addition of Fe could obviously decrease the losing of V2 O5 at high temperature, which greatly decreased the toxicity of the vanadium-based catalysts in mobile sources. Among the synthesized catalysts, the Fe1-V1/TiO2 showed the highest activity with the NOx conversion efficiency over 90% between 220 ℃ and 420 ℃ due to formation of FeVO4 active sites. Moreover, Fe1-V1/TiO2 exhibited excellent thermal stability at high temperature and sulfur resistance.