Infra-red spectroscopic study of the adsorption of water, methanol and acetone on synthetic X and Y zeolites

Abstract

The adsorption of water, normal and deuterated methanol and acetone on NaX, NaY, CaX, CaY zeolites and Aerosil was studied using i.r. spectroscopy. The usual bands at 3745, 3690, 3650, 3400 (very broad), 1640 cm^–1, and the corresponding OD bands were found with all zeolites studied. In the adsorption of methanol and acetone, bonding mainly to cations, but also to the framework of the zeolite is assumed. Rapid deuterium exchange between the OD group of CD₃OD and the zeolite was observed, whereas the CD₃ group remained unaffected. With [²H₆]acetone however, exchange with CD₃ groups was found. This exchange is possibly due to a strong interaction between the CD₃ groups of acetone and the oxygen ions of the zeolite. In contrast to the liquid and gas phase spectra of acetone, the band at 2920 cm^–1(symmetric CH₃ stretching) is the strongest CH₃ band. This is also ascribed to interaction with the oxygen ions of the zeolite.