Shape selective adsorption of olefins on Bronsted acidic OH (OD) groups onferrierite studied-by FT-IR

Adsorption of n-olefins (less than or equal to C-4) on a ferrierite (FER) z eolite was observed by infrared (IR) spectroscopy. Ethene and propene adsor bed selectively on the acidic OH (OD) groups in the small pores of FER, whi le butenes adsorbed also on the silanol groups on the external surface at c a. 200 K, a part of which transferred to tbe;acidic sites upon increase in temperature. This indicates the existence of energy barriers for intercalat ion of butenes into the FER pores. The facility among butenes for migration to the FER pores was found to be in the order trans-butene > 1-butene > ci s-2-butene. (C) 2000 Elsevier Science B.V. All rights reserved.