Mn/TiO2 and Mn–Fe/TiO2 catalysts synthesized by deposition precipitation—promising for selective catalytic reduction of NO with NH3 at low temperatures

Abstract Mn/TiO 2 and Mn–Fe/TiO 2 catalysts have been prepared by impregnation (IMP) and deposition-precipitation (DP) techniques and characterized by N 2 physisorption, XRPD, NH 3 -TPD, H 2 -TPR, XPS and TGA. 25 wt% Mn 0.75 Fe 0.25 Ti-DP catalyst, prepared by deposition precipitation with ammonium carbamate (AC) as a precipitating agent, showed superior low-temperature SCR (selective catalytic reduction) of NO with NH 3 . The superior catalytic activity of the 25 wt% Mn 0.75 Fe 0.25 Ti-DP catalyst is probably due to the presence of amorphous phases of manganese oxide, iron oxide, high surface area, high total acidity, acid strength and ease of reduction of manganese oxide and iron oxide on TiO 2 in addition to formation of an SCR active MnO x phase with high content of chemisorbed oxygen (O α ). The optimum catalyst might be used as tail-end SCR catalysts in, e.g., biomass-fired power plants and waste incineration plants.