The effect of K deactivation on V2O5/WO3-TiO2 and Ce-doped V2O5/WO3-TiO2 catalysts in the selective catalytic reduction (SCR) of NOx 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% NOx 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.
Keywords: Alkali deactivation; Ammonia; Nitrogen oxides; Selective catalytic reduction; V(2)O(5)/WO(3)-TiO(2).
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