Selective Catalytic Reduction of NO_x by NH₃ over Mn-Promoted V₂O₅/TiO₂ Catalyst

Abstract

The effect of Mn on the catalytic performance of V2O5/TiO2 catalyst for the selective catalytic reduction of NO x by NH3 (NH3-SCR) has been investigated in this study. It was found that the added Mn significantly enhanced the activity of V2O5/TiO2 catalyst for NH3-SCR below 400 °C. The redox cycle (V4+ + Mn4+ ↔ V5+ + Mn3+) over Mn-promoted V2O5/TiO2 catalyst plays a key role for the high catalytic deNO x performance. The redox cycle promotes the adsorption and activation of NH3 and NO, forming more reactive intermediates (NH4 +, coordinated NH3, NO2, and monodentate nitrate species), thus promoting the NH3-SCR to proceed.

Activity enhancement of WO3 modified Fe2O3 catalyst for the selective catalytic reduction of NO by NH3

“…Catalyst Surface area (m 2 g À1 ) Pore volume (cm 3 g À1 ) Pore diameter (nm) 1147 cm À1 were assigned to the asymmetric and symmetric bending vibrations of coordinated NH 3 [35,36]. With increasing temperature, the peaks related to the scissoring vibration mode of NH 2 species (1562 cm À1 ) [37] and asymmetric bending vibrations of NH 4 + species on Brønsted acid sites (1430 cm À1 ) appeared [38].…”

MnO supported on Fe–Ti spinel: A novel Mn based low temperature SCR catalyst with a high N2 selectivity

“…Therefore, the low temperature SCR catalysts, which are placed downstream of the electrostatic precipitator and desulfurizer, are strongly demanded [5]. Mn based SCR catalysts, for example Mn/TiO 2 [6,7], Mn-Fe/TiO 2 [8], MnO x -CeO 2 [9,10], MnO x -CeO 2 /TiO 2 [11,12], Mn promoted V 2 O 5 /TiO 2 [13] and Mn-Fe spinel [14], show an excellent SCR activity at low temperatures. However, Mn based catalysts are extremely restricted in the low temperature SCR reaction for at least two reasons: the lower N 2 selectivity and the deactivation by SO 2 [5,15].…”

Research Status and Prospect on Vanadium-Based Catalysts for NH3-SCR Denitration

“…The redox cycle (V 4+ + Mn 4+ ↔ V 5+ + Mn 3+ ) reduces the energy required for electron transfer between Mn and V active sites, and promotes the adsorption and activation of NH 3 and NO. Mn 3+ is conducive to NH 3 -SCR reactions due to its ability to induce the formation of more surface chemisorbed oxygen [40]. In Cu-V/TiO 2 catalysts, the copper species exist mainly as Cu 2+ in CuV 2 O 6 , Cu 2 V 2 O 7 or CuO.…”