Localization and migration of exchange cations in dehydrated polycationic forms of X-type zeolite by EPR

EPR has been used to investigate the influence of dehydration conditions on the localization and migration of cations in type-X zeolites, formed without a binder. It has been found that the conditions of dehydration have a strong influence on the migration of the cations to less accessible locations in the crystal lattice (S1). Rehydration results in the reverse shifting of the cations to locations in accessible places of the zeolite cavities. The described “shuttle• effect of the migration of the cations during dehydration and rehydration can evidently be extended also to other cations and types of zeolites.