Selective Catalytic Reduction of NOx with Ammonia and Hydrocarbon Oxidation Over V2O5–MoO3/TiO2 and V2O5–WO3/TiO2 SCR Catalysts

The NH 3 -SCR performance in the presence of short and long chain hydrocarbons (propylene and dodecane) as well as of formaldehyde was investigated for a series of V 2 O 5 –MoO 3 /TiO 2 (VMoTi) and V 2 O 5 –WO 3 /TiO 2 (VWTi) catalysts. The results demonstrate that vanadium oxides act as the main catalytically active component for NO x conversion, hydrocarbon (HC) and formaldehyde oxidation. Among VMoTi and VWTi materials with different vanadium loading, the catalysts containing 3 wt% V 2 O 5 lead to the highest catalytic activity. The ability to simultaneously remove NO x , HC and HCHO over VMoTi is inferior to that of the conventional WO 3 -based catalyst. However, VMoTi exhibits higher CO 2 selectivity, especially during oxidation of long-chain HCs, which represents an important advantage for a possible multifunctional catalyst. Apart from CO, formaldehyde was detected as byproduct during HC oxidation for both catalyst formulations.