NO-NH3-O-2 reaction catalyzed by V2O5/AC at low temperatures - Effects of SO2, V2O5 loading and reaction temperature

The effects of SO2, V2O5 loading and reaction temperature on the activity o f activated carbon supported vanadium oxide catalyst have been studied for the reduction of NO with NH3 at low temperatures (150-250 degrees C). It is found that SO2 significantly promotes the catalyst activity. Both V2O5 loa ding and reaction temperature are vital to the promoting effect of SO2. The catalysts with V2O5 loadings of 1-5 weight percent have a positive effect on the promotion of SO2, while the catalysts with V2O5 loadings of above 7 weight percent have not such an effect or show a negative effect. At lower temperatures (<180 degrees C) SO2 poisons the catalyst but at higher temper atures promotes it. The reason of the SO2 promotion was also discussed; it may results from the formation of SO42- On the catalyst surface, which incr eases the surface acidity and hence the catalytic activity.