The effect of self-doping Ti3+ into V2O5/TiO2 catalysts on the activity of the catalysts was assessed by the selective catalytic reduction of NOX with NH3 (NH3-SCR). 0.2-V2O5/TiO2 (Al(acac)(3):TBOT = 0.2%) catalyst had the highest catalytic activity at low-temperature range. The as-prepared catalysts are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), H2 temperature-programmed reduction (H-2-TPR), NH3 temperature-programmed desorption (NH3-TPD), surface area and pore structure. XPS and EPR were used to confirm the existence of Ti3+ and oxygen vacancy in the catalysts. The specific surface area, surface acidity, reducibility and valence state of the active components of the catalysts are significantly affected by the self-doping of Ti3+. This work would lead to a new strategic design of Ti3+ self-doped catalysts with fine structure and that can efficiently improve low-temperature SCR performance. (C) 2020 Elsevier Inc. All rights reserved.