MnOx/CeO2-ZrO2-Al2O3 (MnOx/CZA) catalysts with different amounts of manganese loading were prepared by incipient wetness impregnation method for selective catalytic reduction (SCR) of NO with NH3 at low temperature. The catalysts were characterized by N-2 adsorption-desorption measurement, XRD, XPS, and H-2-TPR. Catalytic activity tests reveal that the MnOx/CZA catalyst with 10% manganese loading has the best catalytic activity, almost 90% NO is translated to N-2 in the temperature range of 143-300 degrees C. The highly dispersed MnOx species, the good oxidation activity of NO to NO2, the existent synergistic effect between the manganese and cerium oxides, and the various oxidation states of manganese oxides may be the main reasons for the best SCR activity. In addition, the SCR activity is slightly influenced in the presence of SO2 and H2O, while such effect is restorable after heating treatment. (C) 2011 Elsevier B.V. All rights reserved.