Preparation of High Catalytic Active Mn-La_0.5/TiO₂ Denitration Catalyst by In Situ Deposition Method

Mn-La-0.5/TiO2 denitration catalysts were prepared by impregnation, combustion, coprecipitation, reverse coprecipitation, and in situ deposition method, and their catalytic activities were compared. The catalyst prepared by the in situ deposition method had the highest catalytic activity and N-2 selectivity with a T80 of 104.8 degrees C, a NO conversion of up to 100%, and a temperature window of 104.8-365.6 degrees C. The water and sulfur resistance of the catalysts prepared by the in situ deposition method and the coprecipitation method were compared. The elemental valence state, composition, redox ability, and surface acidic sites of the catalysts were analyzed by XPS, XRF, H-2-TPR and NH3-TPD. The adsorption behavior and NH3-SCR reaction of the catalysts were investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy. Results showed the catalyst prepared by the in situ deposition method had better water and sulfur resistance, higher Mn4+ content, H-2 consumption and medium acidic sites, and faster adsorption rate of NH3 and NO when compared with those prepared by other methods. The NH3-SCR reaction on two catalysts followed the Eley-Rideal mechanism, and "fast SCR" played a key role in the reaction. [GRAPHICS] .