Synergistic Removal of NO_x and VOCs from Flue Gas on Mn-Based Catalysts

The elimination of these two pollutants is crucial since NO_x and VOCs have recently been found to be the main atmospheric pollutants in solid material combustion procedures. The synergistic removal of pollutants within the denitrification zone of SCR suffered from narrow temperature window and low activity. In this study, co-precipitation was employed to create γ-Al₂O₃ doped Mn-based composite catalyst materials. The link between γ-Al₂O₃ addition and catalytic performance was explored using XRD, SEM, and other characterisation means. The results of the activity tests demonstrated that the MnCoAlO_x-7% catalyst was more than 90% effective at denitrification over an extensive temperature spectrum (95–310 °C) and 90% effective for benzene conversion at 195 °C. In the synergistic elimination process, benzene promoted the NH₃-SCR reaction, whereas NO_x enhances benzene oxidation at low temperatures, inhibits it at middle and high temperatures, and has no effect at high temperatures. Reaction mechanism studies had shown that benzene facilitated the formation of amides from NH₃ and promoted nitrites conversion to improve denitrification efficiency during synergistic removal; NO_x reduced the intermediates produced by benzene oxidation at medium and high temperatures, leading to a decrease in benzene removal.