Selective catalytic reduction of NO_x with NH₃ over a V₂O₅/TiO₂ on silica catalyst

The catalytic properties of various supported and unsupported vanadium oxide based catalysts for the Selective Catalytic Reduction of NO_x with NH₃ (SCR) are investigated. It is concluded, that in order to achieve good selectivity in the SCR, the number of active sites favouring SCR has to be increased at the cost of sites favouring ammonia oxidation. This can be achieved by the application of the active vanadium oxide onto a suitable support. A specific catalyst preparation procedure is described which enables the application of vanadium oxide onto TiO₂-adlayered silica. The thus prepared catalyst is shown to exhibit the desired properties, that is, a high selectivity and good activity in the Selective Catalytic Reduction of NO_x with NH₃.