Synergistic Promotion Effect between NO_<i>x</i> and Chlorobenzene Removal on MnO_<i>x</i>–CeO₂ Catalyst

Abstract

Developing new technologies for the simultaneous removal of NO _x and dioxins from metallurgical facility and waste incinerator emissions remains challenging. Here, we present a new synergistic improvement effects of NO _x and chlorobenzene (CB) on the MnO _x-CeO₂ catalyst. CB promoted both the NO _x conversion and N₂ selectivity below 300 °C during the NO _x reduction process, in which the MnO _x-CeO₂ catalyst caused the undesired side reactions due to the over-oxidation of NH₃. Meanwhile, NO _x and NH₃ promoted the CB oxidation activity above 100 °C in the presence of O₂. On the basis of the diffuse reflectance infrared Fourier transforms and kinetic studies, the promotion was due to the separation of the MnO _x-CeO₂ catalyst into different temperature windows: NO _x reduction at 100-200 °C and CB oxidation at 200-300 °C. The side reactions mainly occurred above 200 °C, which is suppressed by the coverage and activation of CB on catalyst surface.