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

The NH3-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 V2O5–MoO3/TiO2 (VMoTi) and V2O5–WO3/TiO2 (VWTi) catalysts. The results demonstrate that vanadium oxides act as the main catalytically active component for NOx conversion, hydrocarbon (HC) and formaldehyde oxidation. Among VMoTi and VWTi materials with different vanadium loading, the catalysts containing 3 wt% V2O5 lead to the highest catalytic activity. The ability to simultaneously remove NOx, HC and HCHO over VMoTi is inferior to that of the conventional WO3-based catalyst. However, VMoTi exhibits higher CO2 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.