Ammonium Ion Enhanced V(2)O(5)-WO(3)/TiO(2) Catalysts for Selective Catalytic Reduction with Ammonia

Selective catalytic reduction (SCR) is the most efficient NO(X) removal technology, and the vanadium-based catalyst is mainly used in SCR technology. The vanadium-based catalyst showed higher NO(X) removal performance in the high-temperature range but catalytic efficiency decreased at lower temperatures, following exposure to SO(X) because of the generation of ammonium sulfate on the catalyst surface. To overcome these limitations, we coated an NH(4)(+) layer on a vanadium-based catalyst. After silane coating the V(2)O(5)-WO(3)/TiO(2) catalyst by vapor evaporation, the silanized catalyst was heat treated under NH(3) gas. By decomposing the silane on the surface, an NH(4)(+) layer was formed on the catalyst surface through a substitution reaction. We observed high NO(X) removal efficiency over a wide temperature range by coating an NH(4)(+) layer on a vanadium-based catalyst. This layer shows high proton conductivity, which leads to the reduction of vanadium oxides and tungsten oxide; additionally, the NO(X) removal performance was improved over a wide temperature range. These findings provide a new mothed to develop SCR catalyst with high efficiency at a wide temperature range.