A series of V2O5-CeOX/TiO2-carbon nanotube composites were prepared by sol-gel method and their catalytic activity for the reduction of NOX with NH3 was compared. V2O5CeOX/TiO2 (Ce/V= 9) achieved a NOX removal efficiency of 92% and 98% at 200 degrees C and 250 degrees C, respectively. SEM, XRD, XPS, BET, Raman, TPD and TPR were employed to probe the promotional effect of CeOX. The appearance of Ce3+ is found to increase chemisorbed oxygen thus facilitates the catalytic reduction of NOX. The poisoning effect caused by SO2 was found to depend on temperatures and gas velocity strongly. Moreover, the existence of excess oxygen was found to be essential (2% of O-2 compared to 500 ppm NOX) to keep high SCR activity. (C) 2012 Elsevier B.V. All rights reserved.