Assignment of the hydroxyl bands in the infrared spectra of zeolites X and Y. Part 1.—Na—H zeolites

Abstract

The infrared spectra of zeolites X and Y were recorded in the hydroxyl stretching region under high resolution conditions. The samples varied in their Al and proton content. The spectra were broken down into six different components. The selection of this number of components was based on reproducible details appearing in the high resolution spectra. An assignment for the different components is proposed, which considers the four different types of oxygen ions as possible sites for proton location. The narrow band at 3650 cm^–1 is assigned to O₁—H hydroxyl groups, while the broad and asymmetric band at 3550 cm^–1 contains components due to O₂—H, O₃—H and O₄—H groups.