Promotional Effect of Pr-Doping on the Nh3-Scr Activity over the V2o5-Moo3/Tio2 Catalyst

V2O5-MoO3/Pr6O11-TiO2 catalysts were prepared by means of an impregnation method and TiO2 supports (loped with different amounts of Pr were synthesized via a sol-gel method. The evaluation of selective catalytic reduction (SCR) activity indicated the catalysts with high activity and N-2 selectivity in a temperature range of 220-400 degrees C. And the Pr-doped catalyst also exhibited good resistance to SO2 and H2O. The catalysts were characterized by means of X-ray diffraction (XRD), N-2 adsorption-desorption (BET), X-ray photoelectron spectrometer (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). The results showed that the specific surface areas of Pr-doped V2O5-MoO3/TiO2 catalysts were larger than that of the V2O5-MoO3/TiO2 catalyst. Furthermore, the addition of Pr on V2O5-MoO3/TiO2 catalyst could give more NH3 adsorption species, chemisorbed oxygen species, bridged nitrate species and the numbers of Bronsted acid sites, resulting in an enhance in the catalytic activity for NH3-SCR of NOx.