In the selective catalytic reduction (SCR) of NO by ammonia, over-exchanged
Fe-ZSM-5 prepared by sublimation of FeCl3 into H-ZSM-5, shows superior cat
alytic activity and stability in a wide temperature range; its activity is
promoted by the presence of water in the feed while SO2 is a weak poison at
low but a promoter at high temperatures; its remarkable durability towards
H2O and SO2 makes this zeolite catalyst a potential choice in Denox applic
ations for stationary sources and heavy Diesel engines with ammonia or urea
reductants.