COMPARISON OF ION EXCHANGE PROPERTIES OF ZEOLITES X AND Y

Thermodynamic and thermochemical aspects have been compared for exchanges of the monovalent cations Li2+, Na+, K+, Rb+ and Cs+, and the divalent ions Ca2+, Sr2+ and Ba2+ in zeolite Na-X containing initially 87 Na+ ions per unit cell and in zeolite Na-Y containing initially 52 Na+ and 5 H+ per unit cell. These two zeolites both have the aluminosilicate framework of faujasite, so that the comparison has served to show effects of changing the cation densities upon heats, standard free energies, standard entropies and selectivities of the exchange reaction. Explanations were possible for most of the observed differences. © 1969.