LAUSR

FeOx, MnOx and Fe–Mn–Ox catalysts were prepared by the co-precipitation method and used for the selective catalytic reduction (SCR) of NOx by NH3 at low temperature. Fe–Mn–Ox catalyst showed the best catalytic activity and above 80% NOx conversion was obtained at 50–150 °C. Nearly 80% N2 selectivity of Fe–Mn–Ox catalyst was acquired at the whole temperature range. The excellent low-temperature SCR activity and N2 selectivity were ascribed to the abundant surface acid sites, the formation of Fe–O–Mn species, co-existence of multiple valence states (Mn4+, Mn3+ and Mn2+) and the proper redox ability. In addition, the interaction between Fe and Mn species over the Fe–Mn–Ox catalyst was responsible for the improvement of SCR performance and N2 selectivity.Graphical AbstractFe–Mn–Ox catalysts were prepared by the co-precipitation method and used for the selective catalytic reduction (SCR) of NOx by NH3 at low temperature. The formation of Fe–O–Mn species contributed to the co-existence of multiple valence states (Mn4+, Mn3+, Mn2+, Fe3+ and Fe2+), resulting in an increase in catalytic activity and N2 selectivity. Besides, the abundance of acid sites was responsible for the superior N2 selectivity.