Effect of redox promoters (CeOx and CuOx) and surface sulfates on the selective catalytic reduction (SCR) of NO with NH3 by supported V2O5-WO3/TiO2 catalysts

A series of TiO 2 -supported MO x catalysts (M=V, W, Ce, Cu and S) were investigated for their SCR activity. In situ Raman spectroscopy indicated that the supported phases completely dispersed as surface sites on support. IR revealed VO , WO SO anchored at both CeO /CuO sites. The number Lewis acid decreased with addition basic (CeO ) acidic (VO /WO in all catalysts, unpromoted Ce-promoted catalysts. introduced Brønsted redox promoters increased NO conversion, but impregnation inhibited effect due to (SO )-base interactions. reaction was shown efficiently proceed via either NH 3 * or 4 + species, resolving long-standing dispute involvement these species reaction. • Redox promoted V O 5 -WO /TiO its Impregnated Ti hydroxyls. Catalysts only highly active. improved activity catalyst. impaired acid-base