Enhancement Of Scr Performance Of Monolithic Mn-Ce/Al2o3/Cordierite Catalysts By Using Modified Deposition Precipitation Method

Mn-Ce catalysts have been widely studied for low-temperature selective catalytic reduction (SCR) of NOx with NH3; however, most of them are powdery or granular. Monolithic catalysts which are more suitable for practical industrial applications still need detailed exploration. In this research, a series of monolithic Mn-Ce/Al2O3/cordierite catalysts were prepared by impregnation (IMP), deposition precipitation (DP), and modified deposition precipitation (MDP) methods. The catalyst MDP3 which depositing alumina and MnOx-CeOx simultaneously for three times by MDP method showed the best activity, and it performed much better at low temperature than the catalysts prepared by IMP and DP methods. MDP3 also showed the best resistance to H2O and SO2. It was thought that Mn-Al and Mn-Al-Ce clusters formed in the preparation of MDP3 and enhanced the interaction between the mixed oxides, as indicated by the characterization results. MDP3 prepared by MDP method showed the largest BET surface area, good redox capabilities, and the highest atomic ratios of Ce3+ and O-b. Hence, MDP was proved to be an effective method to enhance the interaction between the washcoat and the active phase, which resulted in preparing a good performance monolithic SCR catalyst.