Selective catalytic reduction of NO by NH3 over high surface area vanadia-silica catalysts

Abstract A series of vanadia-silica catalysts (6.5 wt.% V 2 O 5 ) have been prepared by three different sol–gel routes. All samples display high surface areas, even for the macroporous samples. XRD and Raman spectroscopy suggests that vanadium is present in a different surrounding and coordination, depending on the specific preparative sol–gel route applied. Room temperature NH 3 –DRIFT analysis indicated the presence of both Bronsted and Lewis acid sites. After heating at 523 K these bands disappeared. XPS analysis show that most of the vanadium is encapsulated in the silica framework. SCR activities of NO by NH 3 were investigated in the presence of SO 2 . It was demonstrated that the choice of preparative route is important in obtaining NO reduction below 573 K.