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

摘要

In this paper, three kinds of Mn-based catalysts over gamma-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 gamma-Al2O3 achieving the highest toluene conversion and ozone decomposition efficiency. Key operating parameters of reaction temperature, initial toluene concentration and O-3/C7H8 ratio were investigated over MnOx/gamma-Al2O3 to get the optimal daily operation condition. The suitable temperature range was 100 similar to 120 degrees 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.