Activity of Selective Catalytic Reduction of NO over V2O5/TiO2 Catalysts Preferentially Exposed Anatase {001} and {101} Facets

Three V2O5/TiO2 catalysts with V2O5 loading of 3 wt% were fabricated by wet impregnation, in which the TiO2 supports had different crystal types, including the octahedral TiO2 (preferentially exposed anatase {101} facets, labeled as TiO2-O), the sheet TiO2 (preferentially exposed anatase {001} facets, labeled as TiO2-S), and the commercial TiO2 (TiO2-P25), giving the three corresponding catalysts, respectively. The activities and the effects of H2O and SO2 over the V2O5/TiO2 catalysts for the selective catalytic reduction (SCR) of NO by NH3 were investigated. It was found that the crystal facets of TiO2 nanoparticles played an essential role in the catalytic activity. The V2O5/TiO2-S catalyst exhibited the better catalytic activity than the V2O5/TiO2-O and V2O5/TiO2-P25 catalysts for the NH3-SCR reaction. The N-2 sorption isotherm measurement (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (H-2-TPR), temperature-programmed desorption (NH3-TPD), X-ray photoelectron spectra (XPS) and in-situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) characterizations showed that the good dispersion and reducibility of vanadium species, and the high concentration of chemisorbed oxygen of the V2O5/TiO2-S catalyst could be responsible for the enhancement in the activity of NH3-SCR reaction over the catalyst.