Fe-V/TiO₂ catalysts for selective catalytic reduction of NO_x with NH₃ in diesel exhaust

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 V₂O₅ 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 NO_x 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.