A series of N-doped graphene (NG) and TiO 2 supported MnO x –CeO 2 catalysts were prepared by a hydrothermal method. The catalysts with different molar ratios of Mn/Ce (6 : 1, 10 : 1, 15 : 1) were investigated for the low-temperature selective catalytic reduction (SCR) of NO x with NH 3. The synthesized catalysts were characterized by HRTEM, SEM, XRD, BET, XPS, and NH 3-TPD technologies. The characterization results indicated that manganese and cerium oxide particles dispersed on the surface of the TiO 2–NG support uniformly, and that manganese and cerium oxides existed in different valences on the surface of the TiO 2–NG support. At Mn element loading of 8 wt%, MnO x –CeO 2(10 : 1)/TiO 2–1%NG displayed superior activity and improved SO 2 resistance. On the basis of the catalyst characterization, excellent catalytic performance and SO 2 tolerance at low temperature were attributed to the high content of manganese with high oxidation valence, extensive oxidation of NO into NO 2 by CeO 2 and strong NO adsorption capacity, and electron transfer of N-doped graphene.