Effect of V2O5 loading of V2O5/TiO2 catalysts prepared via CVC and impregnation methods on NOx removal

In this study, V2O5/CVC-TiO2 materials with different concentrations of V2O5 were prepared via chemical vapor condensation (CVC) and impregnation. The catalytic activities of these materials were tested and the physicochemical characteristics were analyzed using XRD, BET, FT-IR spectroscopy, XPS, HR-TEM, EDX mapping, H-2-TPR, and NH3-TPD. The NOx removal efficiency of the V2O5/CVC-TiO2 catalysts was higher than that of the V2O5/P25-TiO2 catalysts and increased with increasing V2O5 concentration. At 200 degrees C, the highest NO conversion was observed using 7 and 10 wt.% V2O5/CVC-TiO2 catalysts. The NO conversion curve reached a plateau corresponding to the maximum conversion when the V2O5 content was greater than 7 wa. The V2O5/CVC-TiO2 catalyst comprised mainly anatase-phase TiO2 and well-dispersed V2O5. A greater concentration of V (well-balanced V4+/V5+) species existed on the V2O5/CVC-TiO2 catalyst surface. H-2-TPR and NH3-TPD testing confirmed that the V2O5/CVC-TiO2 catalyst is highly reducible and has many acidic sites. (C) 2013 Elsevier B.V. All rights reserved.