An analysis of elementary processes of water desorption from zeolites of type a Part II. Zeolites with bivalent counterions

Abstract

DSC and EGA were used to follow the process of water desorption from synthetic MgA, ZnA and CdA zeolites. Applying a semi-empirical algorithm the complex experimental curves were resolved into elementary ones. It turned out that in zeolites with bivalent cations there are four phases of sorbed water. Sorption heats were determined for each individual phase. The NMR spectra of water on a CaA zeolite were investigated. They also point out the existence of four phases. On the basis of the results obtained a possible model of water sorption on synthetic zeolites with bivalent cations is discussed.