Properties of Vanadia SCR Catalyst

Vanadia SCR catalysts contain V2O5 as the active component. V2O5 is typically impregnated on an anatase Ti02 support together with WO3 to stabilize the vanadia and increase thermal durability. Typical compositions are 1-3 % V2O5 and 10 % WO3 on the Ti02 support [2, 15]. 

For mobile applications, the SCR catalyst material is either washcoated onto an inert monolith substrate or the catalyst material is extruded or produced in a way 

The shape of the cross-section of the monolith channels may be of different geometry for both coated and extruded SCR catalysts. A very common shape is the square geometry as in Fig. 3.3, however, other forms like triangular are also existing. 

Monolith wall consisting of catalytically active material 

87 to 80 m /g [2]. Further increase of V2O5 concentration to 3.56 % reduced the SSA to 64 m /g. High V2O5 concentration also promotes the anatase to rutile phase transition, which will lead to lower thermal stability of the catalyst [2]. Vanadia concentrations above ca 3 % will also lead to loss in selectivity of the catalyst and increased formation of N2O [15, 22, 23]. 

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