Enhancement of SO2 Resistance on Submonolayer V2O5-MnO2/CeO2 Catalyst by Three-Dimensional Ordered Mesoporous CeO2 in Low-Temperature NH3-SCR

Developing low-temperature (<300 degrees C) SO2-tolerant catalysts for NOx reduction is a challenge. A catalyst architecture of three-dimensional (3D) ordered mesoporous CeO2 supported by submonolayer V2O5 and MnO2 (V2O5-MnO2/3DCeO(2)) was successfully prepared to promote the SO2 resistance in low-temperature selective catalytic reduction (SCR). The 3D ordered mesoporous channels were retained even after the exposure of the catalyst to SO2 and H2O. The presence of a highly 3D ordered mesoporous structure of V2O5-MnO2/3D-CeO2 can lead to high vapor pressure, which was beneficial for ammonium bisulfate vaporization and decomposition, eventually protecting the active vanadia sites. The stable active crystalline V2O5 species and the formative cerium sulfate promoters were crucial for determining the low-temperature SCR activity and SO2 tolerance in the presence of SO2 and H2O. Therefore, our V2O5-MnO2/3D-CeO2 catalyst delivered a large temperature range of 250-320 degrees C with NO conversion above 95%. The 3D ordered mesoporous channels of the V2O5-MnO2/3D-CeO2 catalyst provided an effective way to improve the SO2 resistance at 250 degrees C.