Effect of Sn on MnO –CeO2 catalyst for SCR of NO by ammonia: Enhancement of activity and remarkable resistance to SO2

Abstract SnO 2 –MnO x –CeO 2 catalysts prepared by a co-precipitation method have been investigated for NH 3 -SCR reaction. The catalyst with a molar ratio of Sn / (Sn + Mn + Ce) = 0.1 showed complete conversion of NO in a temperature range of 80–230 °C. A remarkably high activity, N 2 selectivity and SO 2 resistance was obtained at 200–500 °C, attributed to the significantly enhanced Lewis acid sites that are created by surface sulfation during SO 2 -containing SCR reaction.