Effect of Sn on MnOx–CeO2 catalyst for SCR of NOx by ammonia: Enhancement of activity and remarkable resistance to SO2

SnO2–MnOx–CeO2 catalysts prepared by a co-precipitation method have been investigated for NH3-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, N2 selectivity and SO2 resistance was obtained at 200–500 °C, attributed to the significantly enhanced Lewis acid sites that are created by surface sulfation during SO2-containing SCR reaction.

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► The SnO2-MnOx-CeO2 catalyst showed 100% conversion of NO at 80–230°C.
► A remarkably high N2 selectivity and SO2 resistance was obtained at 200–500°C.
► The Lewis acid sites are significantly enhanced by SO2 poisoning in SCR reaction.