A novel template-free approach, the controlled thermal decomposition of single-phase Fe-Mn binary oxalate, was proposed and used to synthesize mesoporous Fe-Mn binary oxide, which possessed homogeneous worm-like mesopores (4-5 nm) and high surface areas above 200 m(2)/g. The catalyst was efficient in the catalytic removal of low-concentration NO at room temperature: 100% removal of 10 ppm NO in the first 4h at a high space velocity of 40,000h(-1) on a Fe-Mn binary oxide with a Fe/Mn ratio of 1/4 calcined at 300 degrees C. Catalysts with other Fe/Mn ratios or calcined at higher temperatures showed lower NO removal performances. A synergetic effect between Mnn+ and Fen+ was proposed and believed to be responsible for the catalytic conversion of NO and O-2 into NO2, which was subsequently adsorbed and/or absorbed as nitrates on the binary oxide. (C) 2013 Elsevier B.V. All rights reserved.