A new view on the relations between tungsten and vanadium in V2O5WO3/TiO2 catalysts for the selective reduction of NO with NH3

► Comparative EPR studies of W-free and W-containing V2O5/TiO2 catalyst show extensive V oxide island formation in the former, more isolated V oxide species in the latter. ► TPR allows differentiating surface W oxide species in contact with surface V oxide species from those interacting with surface W oxide species only. ► Spontaneous arrangement of surface V and W oxide species on anatase leads to a well-mixed surface oxide phase instead of segregates surface V (W) oxide islands.