Study on the Mechanism of No Reduction by Nh3 Over Mncuox Catalysis and the Influence Mechanism of Co

Abstract

A series of CuMnOx catalysts were prepared the coprecipitation method to explore the effect of CO participation on NH3-SCR reaction. The result showed that the CM-3 sample reached 100% the conversion of CO and NO at a temperature lower than 175 ° C, this primarily occurs because the correct ratio of Cu and Mn is conducive to the formation of a solid solution, improves the synergy between Mn and Cu leads to stronger redox performance. Moreover, the interaction principle of CO participating in NH3-SCR reaction is thoroughly investigated through, in situ DRIFTS and DFT. First, NH3 has varying adsorption modes at different temperatures, at low temperatures, it predominantly combines with surface oxygen through hydrogen bonds; it is mainly a NH4+ species when it rises. Second, NH3 and CO compete for the same active center, which significantly affects the catalytic reaction on the sample surface. Further, it is confirmed that the deposition of CO32- is the main reason for the decline in of activity. Finally, the improvement in N2 selectivity in the reaction with CO participation is due to the N2O produced not being directly released, but being further reduced to N2 through species such as CO.

Keywords: Multi pollutant collaborative control, NH3-SCR, CO-NO, CO oxidation, reaction mechanism