IR SPECTROSCOPIC STUDY OF ACID SITES IN MORDENITES FLUORINATED UNDER MILD CONDITIONS

Results obtained by IR and EPR spectroscopy show that treatment of mor denites with NH4F solution under mild conditions leads to the appearan ce of a large amount of strong Lewis-acid sites, presumably low-coordi nate Si ions. These sites, which enhance the catalytic activity of the fluorinated zeolites, may be considered as alternative active sites i n the transformation of alkylaromatics.