Study of Ce, Sb, and Y exchanged titania nanotubes and superior catalytic performance for the selective catalytic reduction of NOx

Metal exchanged titania nanotube (M-TNT, M = Ce, Sb, and Y) materials were used as supports to prepare manganese confined (Mn/M-TNT) catalysts for the NH3-SCR. All the fresh catalysts showed similar deNO(x) performance with great NOx conversion in the temperature range of 100 350 degrees C. However, after thermal aging, the NH3-SCR activity of Mn/Ce-TNT and Mn/Sb-TNT catalysts has dramatically decreased. Interestingly, the Mn/ Y-TNT catalyst maintained well its good NH3-SCR activity even after thermal aging at 650 degrees C. The tubular morphology and surface area/pore volume are reasonably maintained even after thermal aging at 650 degrees C when TNT exchanged with Y. The loss of active MnO2 (Mn4+) species, active oxygen species, and acid sites on the surface of the Mn/Y-TNT catalyst is significantly prevented during thermal treatment, therefore NH3-SCR activity is well preserved over the thermally aged Mn/Y-TNT catalysts.

Automated summary

Fresh Mn/Ce-TNT and Mn/Sb-TNT catalysts showed good NH3-SCR activity, but a significant decrease in activity was observed after thermal aging, while the Mn/Y-TNT catalyst maintained its good catalytic performance under these conditions.