Controlled Synthesis of Mesoporous CeO2-WO3/TiO2 Microspheres Catalysts for the Selective Catalytic Reduction of NOx with NH3

A series of mesoporous TiO2 supports were synthesized by changing the hydrothermal temperature. Subsequently, CeO2-WO3/TiO2 catalysts were prepared by impregnation method and applied for selective catalytic reduction (SCR) of NOx with NH3. In addition, the morphology of TiO2 changed from microspheres to ellipsoidal microspheres by gradually increasing the hydrothermal temperature which was 120 degrees C, 160 degrees C and 200 degrees C. Obviously, the SCR activity was exhibited in the following order: CeO2-WO3/TiO2-160 > CeO2-WO3/TiO2-120 > CeO2-WO3/TiO2-200. Among, the CeO2-WO3/TiO2-160 catalyst exhibited better catalytic activity for the NH3-SCR reaction. Through a series of characterizations, it was concluded that the mesoporous structure, redox ability and abundant surface acidity of the CeO2-WO3/TiO2 catalyst played a critical role in improving the activity, resistant of H2O and SO2.