MnO _x-Pillared Rectorite Prepared by in Situ Deposition as Efficient Catalysts for Low Temperature NH ₃-SCR: The Influence of Precursors

A series of catalysts containing manganese oxide pillared rectorite were prepared by in situ deposition using different Mn precursors, e.g., Mn(NO3)2, Mn(Ac)2, MnSO4 and MnCl2 to occur redox reaction with KMnO4, respectively. The samples were characterized by XRD, SEM, N2 adsorption, HR-TEM, H2-TPR, NH3-TPD, TPSR and XPS. And the catalytic performances for low temperature NH3-SCR were evaluated for the first time. The results showed that the catalytic performances decreased in the order of MnO2-Ac/Rec > MnO2-Cl/Rec > Mn10/REC-SO42- > Mn10/REC-NO3-, which was closely related with specific surface areas, dispersion of manganese oxide, content of adsorbed oxygen and Mn4+. The Mn10/REC-Ac - catalyst showed the best redox ability, richest Lewis acid sites and best dispersion of MnO2, which was suggested to be the main reasons for its good low temperature NH3-SCR activity. Moreover, even under working conditions with GHSV up to 105,000 h-1, high DeNOx performance was also observed on Mn10/REC-Ac- catalyst.