Interaction of OH groups in NaHY zeolites with physically adsorbed alkanes

Abstract

The interaction of physically adsorbed alkane molecules with OH groups in NaHY zeolites with various degrees of cation exchange was studied by i.r. spectroscopy. The adsorption of alkanes on NaHY zeolites results in a shift of the 3640 cm^–1 OH band to lower frequencies, which is accompanied by an increase in its intensity and half-width. The higher the polarizability of the adsorbed molecules, the greater these effects are. The frequency shift of the 3640 cm^–1 OH band was greater in the case of NaHY zeolite with increasing H content, which may be explained by an increase in the acid strength of these OH groups.