Selective catalytic reduction (SCR) of NOx by AdBlue and NH3 on monolithic V2O5/WO3/TiO2 catalyst was studied under flow conditions realistic for diesel exhaust. The tests provided same standard and fast SCR for AdBlue and NH3 from 150 to 350 degrees C. For standard urea-SCR, axial concentration profiles were checked by monoliths with different lengths evidencing incomplete conversion of urea and isocyanic acid at low temperatures. But SCR was not clearly affected by under-stoichiometric NH3 as substantiated by kinetic analysis. However, above 250 degrees C, SCR was limited by internal mass transport indicated by Weisz-Prater criterion and lower activation barrier. Formation of deposits was investigated at 175 degrees C and below showing some urea around the nozzle, whereas cyanuric acid and biuret additionally formed around the catalyst.