Alkali resistance promotion of Ce-doped vanadium-titanic-based NH3-SCR catalysts

The effect of K deactivation on V₂O₅/WO₃-TiO₂ and Ce-doped V₂O₅/WO₃-TiO₂ catalysts in the selective catalytic reduction (SCR) of NO_x by NH₃ was studied. Ce-doped V₂O₅/WO₃-TiO₂ showed significantly higher resistance to K deactivation than V₂O₅/WO₃-TiO₂. Ce-doped V₂O₅/WO₃-TiO₂ with K/V = 4 (molar ratio) showed 90% NO_x conversion at 350°C, whereas in this case V₂O₅/WO₃-TiO₂ showed no activity. The fresh and K-poisoned V₂O₅/WO₃-TiO₂ and Ce-doped V₂O₅/WO₃-TiO₂ catalysts were investigated by means of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), NH₃-temperature progress decomposition (NH₃-TPD), X-ray photoelectron spectroscopy (XPS) and H₂-temperature program reduction (H₂-TPR). The effect of Ce doping on the improving resistance to K of V₂O₅/WO₃-TiO₂were discussed.