NH3-SCR denitration catalyst performance over vanadium–titanium with the addition of Ce and Sb

Selective catalytic reduction technology using NH3 as a reducing agent (NH3-SCR) is an effective control method to remove nitrogen oxides. TiO2-supported vanadium oxide catalysts with different levels of Ce and Sb modification were prepared by an impregnation method and were characterized by X-ray diffractometer (XRD), Brunauer–Emmett–Teller (BET), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), Raman and Hydrogen temperature-programmed reduction (H2-TPR). The catalytic activities of V5CexSby/TiO2 catalysts for denitration were investigated in a fixed bed flow microreactor. The results showed that cerium, vanadium and antimony oxide as the active components were well dispersed on TiO2, and the catalysts exhibited a large number of d–d electronic transitions, which were helpful to strengthen SCR reactivity. The V5CexSby/TiO2 catalysts exhibited a good low temperature NH3-SCR catalytic activity. In the temperature range of 210 to 400°C, the V5CexSby/TiO2 catalysts gave NO conversion rates above 90%. For the best V5Ce35Sb2/TiO2 catalyst, at a reaction temperature of 210°C, the NO conversion rate had already reached 90%. The catalysts had different catalytic activity with different Ce loadings. With the increase of Ce loading, the NO conversion rate also increased.

NO conversion as a function of reaction temperature over V5CexSby/TiO2 catalysts with different Ce and Sb loadings.A series of V5CexSby/TiO2 catalysts are tested in the NH3-SCR of NO. All vanadium–titanium based catalysts have good low temperature NH3-SCR activity with different Ce and Sb loadings. When the reaction temperature is at 225°C, NO conversion can reach 90% over all the catalysts. With the increasing of the Ce loading, the conversion of NO increases. At 225–400°C, NO conversion can maintain above 90% for all V5CexSby/TiO2 catalysts with a wide temperature window. Addition of antimony (2 wt.%) leads to improving a low temperature NH3-SCR activity. V5Ce35Sb2/TiO2 catalyst exhibits the best catalytic activity for the removal of NO. At 210°C, NO conversion has already reached 90%. The results suggest that the addition of cerium and antimony can especially improve the catalytic activity of the SCR reaction at low temperature.Figure optionsDownload as PowerPoint slide