Design the confinement structure Mn-TNTs@Ce catalyst for selective catalytic reduction of nitrogen oxides with superior SO2 resistance over a wider operation window

The catalytic centers confined in the nanoscale space was an effective approach for lowering reaction energy barrier and shielding confined species from poisoning in NH3-SCR. Herein, we constructed a special nanotube-confined Mn-TNTs@Ce catalyst, where MnOx was confined in TiO2 nanotube (TNTs) via in-situ introduction following Ce ion exchanged into the skeleton of TNTs. The NO conversion on Mn-TNTs@Ce could reach upon 80% even containing 100 ppm SO2, and the N2 selectivity maintained around 100% below 280 °C. The nanotube-confined structure improved the surface acidity to restrain SO2 adsorption, and Ce species acted as protective site protecting Mn from SO2 attacking. Furthermore, the short-range structure Ce-O-Ti promoted the electron transformation between Mn and Ce to suppress the formation of -NH and NH4NO3, resulting in inhibiting the generation of N2O. This work provided an available idea for structural design to improve SO2 resistance and N2 selectivity of Mn-based catalyst for NH3-SCR.