The effect of additives and intermediates on vanadia-based catalyst for multi-pollutant control

Abstract

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