The addition of Ge and Mn to CeO2-WO3 catalysts for NH3-SCR of NOx was investigated. The effect of calcination temperature and the influence of SO2 on SCR activity were studied, and heat treatment with H-2 was used to regenerate sulfated catalysts. The results showed that doping with Ge and Mn enhanced the SCR activity of Ce3W2O(x) (molar ratio of Ce:W = 3:2) at 100-250 degrees C. More than 95% NOx conversions were obtained between 200 and 470 degrees C over (Ce3W2)(0.9)Ge0.1Ox-500 (molar ratio of (Ce + W):Ge = 9: 1, calcined at 500 degrees C) catalyst. The characterization results indicated that the formation of amorphous phase and high atomic ratio of W/Ce on the surface might contribute to the high activity over (Ce3W2)(0.9)Ge0.1Ox-500. The NOx conversions decreased over Ce3W2O(x) series catalysts calcined at 700 degrees C, however, the activities of (Ce3W2)(0.9)Ge0.1Ox calcined at 700 degrees C were higher than those of the others, suggesting the addition of Ge weakened the effect of high calcination temperature. The deactivation of (Ce3W2)(0.9)Ge0.1Ox-500 by SO2 was much slower than that of Ce3W2O(x)-500. The sulfated (Ce3W2)(0.9)Ge0.1Ox-500 catalysts could be easily regenerated by heat treating with H-2 at 300 degrees C since the sulfates species were unstable over these catalysts. H-2 regeneration is an effective way to recycle GeO2-CeO2-WO3 catalyst. (C) 2012 Elsevier B. V. All rights reserved.