10
1.  SCR-Reaction
     NOx + NH3  =  N2 + ...
Side Reactions:
2.  NH3 Oxidation
     NH3 + O2  =  NOx + ...
3.  SO2 Oxidation
     SO2 + O2 = SO3  + ...
All 3 reactions catalysed by V2O5
(1)
without (2),
theoretically
(2)
(3)
Catalyst Performance vs T