Effect of synthesis methods on activity of V2O5/CeO2/WO3-TiO2 catalyst for selective catalytic reduction of NOx with NH3

Abstract The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction (SCR) of NO x by NH 3 . V/Ce/WTi-DP (deposition precipitation) catalyst showed excellent NH 3 -SCR performance, especially the better medium-temperature activity and the less N 2 O formation than V/Ce/WTi-IMP (impregnation). These catalysts were characterized by X-ray diffraction (XRD), Brumauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (H 2 -TPR), and in situ DRIFTS techniques. The XPS and H 2 -TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of O α and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method (DP) contributed to a greater amount of weakly adsorbed NO 2 , monodentate nitrate and NH 3 species with better reactive activity. Meanwhile, the cis-N 2 O 2 2– species, an intermediate for N 2 O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N 2 selectivity for V/Ce/WTi-DP.