A highly effective NbMnCeOx catalyst for NH3-SCR and in situ DRIFTS for investigating the reaction mechanism

Mn0.1Ce0.9Ox and a series of NbmMn0.1−mCe0.9Ox catalysts with different Nb doping ratios were successfully synthesized by the citric acid method. Experimental results indicated that the catalytic performances of the NbmMn0.1−mCe0.9Ox were significantly ameliorated by Nb modification. In particular, the Nb0.06Mn0.04Ce0.9Ox catalyst exhibited over 90% NO conversion in the temperature range of 175–325 °C and had good resistance to SO2&H2O. The characterization results revealed that Nb0.06Mn0.04Ce0.9Ox exhibited a larger specific surface area, superior surface acidity and redox property, higher Mn4+ and oxygen vacancy contents compared to Mn0.1Ce0.9Ox. Furthermore, the more active ad-NH3 and ad-NOx species on the Nb0.06Mn0.04Ce0.9Ox sample also greatly accelerated the NH3-SCR reaction on it.