The additives and intermediates analysis on vanadia-based catalyst for NOx and chlorobenzene co-control

The influences of additives, WO3 and MoO3, on activities of V2O5/TiO2 for NOx and chlorobenzene (CB) removal were investigated. Mo/VTi catalyst exhibited higher selective catalytic reduction of NOx and CB oxidation activities than that of the W/VTi catalyst. These can be due to the higher reactivity of Mo containing catalyst and narrower band gap of Mo d-orbitals. When NO and NH3 were both presented in the flue gas, the CB oxidation activity of Mo/VTi showed a significant decline at relatively low temperature due to the competitive adsorption of hydrocarbon species. Aniline was observed above 550 °C only on the Mo/VTi, which was generated through CB nitration with NO2 and further amination with NH3 at high temperature. The online TG-IR-MS results showed that CCl4 and C2Cl4 acted as the main species accumulated on the used catalyst surface with the elevated temperatures.