A γ-Fe2O3-modified nanoflower-MnO2/attapulgite catalyst for low temperature SCR of NOx with NH3

A mesoporous γ-Fe2O3-modified nanoflower-MnO2/attapulgite (γ-Fe2O3/nf-MnO2–ATP) catalyst was fabricated through a facile hydrothermal method. The results of TEM and XRD indicated that γ-Fe2O3/nf-MnO2–ATP presented a beautiful nanoflower shape and good dispersion. The BET results showed that the specific surface area and pore volume of γ-Fe2O3/nf-MnO2–ATP significantly increased after surface modification with γ-Fe2O3. Also, the XPS and NH3-TPD results illustrated that the γ-Fe2O3 coating could enhance the amounts of surface chemisorbed oxygen and acidic sites. SO2 and H2O tolerance tests and stability tests demonstrated that γ-Fe2O3/nf-MnO2–ATP can effectively inhibit SO2 and H2O poisoning and improve the stability of the catalyst. The superior SCR performance can be attributed to the abundant acid sites, the strong adsorption of NOx, and the formation of more oxygen vacancies as well as metal–metal interactions. Therefore, γ-Fe2O3/nf-MnO2–ATP was proved to be an excellent catalyst for NH3-SCR and may be of interest in other environmental catalysis applications.