Low temperature catalytic ozonation of toluene in flue gas over Mn-based catalysts: Effect of support property and SO2/water vapor addition

[Display omitted] •Toluene catalytic ozonation in flue gas was evaluated under related industrial conditions.•The acidity and oxygen species on catalyst surface was related to catalytic activity.•The effect of SO2 and water vapor in flue gas on toluene oxidation were firstly investigated.•Toluene conversion efficiency could recover as SO2 and water vapor was stopped. In this paper, three kinds of Mn-based catalysts over γ-Al2O3, SiO2 and TiO2 were synthesized to evaluate the toluene catalytic degradation by ozone under the related industrial conditions (i.e., temperature, SO2 and water vapor addition). Results show that the total acid and Mn3+ content on catalyst surface have a positive correlation with catalytic activity, thereby MnOx supported on γ-Al2O3 achieving the highest toluene conversion and ozone decomposition efficiency. Key operating parameters of reaction temperature, initial toluene concentration and O3/C7H8 ratio were investigated over MnOx/γ-Al2O3 to get the optimal daily operation condition. The suitable temperature range was 100∼120 °C, whereas too high or too low temperature both inhibited catalytic activity. Catalyst poisoning occurred as SO2 or water vapor was added, but fortunately, the toluene conversion efficiency could recover once SO2 or water vapor was stopped. Finally, in-situ DRIFTS measurement was carried out to reveal the reaction process and SO2 effect.