The infrared spectra of water sorbed on several synthetic zeolites is discussed in terms of the molecular species present. Three different sets of bands are observed for water as the water content on the zeolite is varied. Evidence for surface OH groups for synthetic zeolites is presented. A technique for reducing the scattered light of zeolite powders by wetting them is suggested. It is possible to study surface OH groups by this technique using D2O as the wetting agent. A mechanism whereby surface OH groups can form in sodium and ammonium zeolites is given. The results obtained for water sorbed on sodium zeolites differs to some extent from those reported previously.
HERMAN A. SZYMANSKI, DENNIS N. STAMIRES, and GREGORY R. LYNCH, "Infrared Spectra of Water Sorbed on Synthetic Zeolites," J. Opt. Soc. Am. 50, 1323-1328 (1960)