Rq. Long et Rt. Yang, Selective catalytic reduction of NO with ammonia over V2O5 doped TiO2 pillared clay catalysts, APP CATAL B, 24(1), 2000, pp. 13-21
Citations number
28
Categorie Soggetti
Physical Chemistry/Chemical Physics","Environmental Engineering & Energy
A series of vanadia doped TiO2-pillared clay (TiO2-PILC) catalysts with var
ious amount of vanadia were studied for selective catalytic reduction (SCR)
of NO by ammonia in the presence of excess oxygen. It was found that the V
2O5/TiO2-PILC catalysts were highly active for the SCR reaction. The cataly
sts showed a broad temperature window, and the maximum NO conversion was hi
gher than that on V2O5/TiO2 catalyst and was the same as the commercial V2O
5 + WO3/TiO2 catalyst. The V2O5/TiO2-PILC catalysts also had higher N-2/N2O
product selectivities as compared to V2O5 doped TiO2 catalysts. In additio
n, H2O + SO2 slightly increased the activities at high temperatures (>350 d
egrees C) for the V2O5/TiO2-PILC catalysts. Addition of WO3 to V2O5 further
increased the activities of the PILC catalysts. These results indicate tha
t TiO2-PILC is a good support for vanadia catalysts for the SCR reaction. I
n situ FT-IR experiment indicated that both Bronsted acid sites and Lewis a
cid sites exist on the catalyst surface, but with a large proportion being
Bronsted acid sites at low temperatures (e.g., 100 degrees C). The reaction
path for NO reduction by NH3 on the V2O5/TiO2-PILC is similar to that on V
2O5/TiO2 catalyst, i.e., N-2 originates from the reaction between gaseous N
O and NH3 adspecies. (C) 2000 Elsevier Science B.V. All rights reserved.