Improved catalytic activity and N 2 selectivity of Fe–Mn–O x catalyst for selective catalytic reduction of NO by NH 3 at low temperature

FeO x , MnO x and Fe–Mn–O x catalysts were prepared by the co-precipitation method and used for the selective catalytic reduction (SCR) of NO x by NH 3 at low temperature. Fe–Mn–O x catalyst showed the best catalytic activity and above 80% NO x conversion was obtained at 50–150 °C. Nearly 80% N 2 selectivity of Fe–Mn–O x catalyst was acquired at the whole temperature range. The excellent low-temperature SCR activity and N 2 selectivity were ascribed to the abundant surface acid sites, the formation of Fe–O–Mn species, co-existence of multiple valence states (Mn 4+ , Mn 3+ and Mn 2+ ) and the proper redox ability. In addition, the interaction between Fe and Mn species over the Fe–Mn–O x catalyst was responsible for the improvement of SCR performance and N 2 selectivity. Graphical Abstract Fe–Mn–O x catalysts were prepared by the co-precipitation method and used for the selective catalytic reduction (SCR) of NO x by NH 3 at low temperature. The formation of Fe–O–Mn species contributed to the co-existence of multiple valence states (Mn 4+ , Mn 3+ , Mn 2+ , Fe 3+ and Fe 2+ ), resulting in an increase in catalytic activity and N 2 selectivity. Besides, the abundance of acid sites was responsible for the superior N 2 selectivity.