Study on the Reaction Performance of Ce- and Co-Modified Mn-Based Catalysts in C<sub>3</sub>H<sub>6</sub>-SCR
Li Yang, Heng Yang, Qing Liu, Fang Liu, Ning Chen
Abstract
The C 3 H 6 -SCR de-NO x technology has received widespread attention due to its significant development potential. Through Mn y /γAl 2 O 3 catalyst activity testing, the catalytic performance of the Mn 5 /γAl 2 O 3 catalyst was the best, and the NO conversion could reach 60% at 275 °C. Afterward, Ce/Co modification was carried out on the Mn 5 /γAl 2 O 3 catalyst to prepare catalysts with different Ce/Co loadings, and activity testing was conducted. It was found that the catalytic performance of the catalyst was significantly improved after doping with promoters, and the improvement of catalytic performance by Ce was much stronger than that of Co, and the doping of Ce also reduced the optimal reaction temperature. Through NO-TPD and H 2 -TPR, it can be found that, after doping with Ce, the catalyst’s ability to adsorb NO and oxidation–reduction were stronger than those of Co-doped catalysts, which explained the higher catalytic performance of Mn 5 /Ce 10 -γAl 2 O 3 catalyst. In a comparison of the characterization results of the Mn 5 /Ce 10 -γAl 2 O 3 catalyst before and after the reaction, it can be found that the Mn 5 /Ce 10 -γAl 2 O 3 catalyst had good reaction stability. The addition of Ce 4+ can lead to the formation of the Mn–O–Ce bridge, thereby strengthening the binding between Mn and O and further promoting the progress of C 3 H 6 -SCR. Finally, through in situ DRIFTS, it was found that the reaction of C 3 H 6 -SCR on the Mn 5 /Ce 10 -γAl 2 O 3 catalyst followed the oxidation–reduction mechanism and generated the important intermediate product −NH.