Szilard–Chalmers cation recoil studies in zeolites X and Y. Part 1.—Ion exchange in zeolites X and Y

Abstract

Isotherms and Kielland plots have been obtained for the exchange of K⁺, NH⁺ ₄, Rb⁺ and Cs⁺ at 25°C in a Na–Y zeolite containing 68 Na⁺ ions per unit cell. Interesting differences have been found in these systems compared with previous studies in Na–X and Na–Y zeolites containing 86 and 56 Na⁺ ions per u.c. respectively. Isotherms have also been obtained for the exchange of Ba²⁺ in Na–X and also Na–Y at 25°C; Co²⁺ in Na–X and Na–Y at 25 and 90°C; Zn²⁺ in Na–X at 25°C; and Cu²⁺ in Na–Y at 25°C. A study has also been made of the redistribution among the various sites of these zeolites X and Y of the cations Cs⁺, Rb⁺, Ba²⁺, Co²⁺, Zn²⁺, Cu²⁺ and La³⁺ as the temperature is increased over the range 25 to 800°C. These cations were initially sited only in the supercages before heating commenced. Interesting results are reported showing the preferences of these cations for the various sites present in these structures.