MnOx-SnO2 Catalysts Synthesized by a Redox Coprecipitation Method for Selective Catalytic Reduction of NO by NH3

MnOx-SnO2 composite oxides prepared by a redox coprecipitation route were tested in selective catalytic reduction of NO by NH3 at low temperatures. The results showed that the MnOx-SnO2 catalyst with a Mn/(Mn+Sn) molar ratio of 75% exhibited the best performance, on which NO conversion of 100% could be achieved at temperatures of 120–200 °C. The characterization results of N2 adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy indicated that the higher surface area, the formation of solid solution between manganese and tin oxides, and the high oxidation state manganese species were responsible for the high catalytic activity of the MnOx-SnO2 catalyst.