Modification of Zeolites and New Routes to Ion Exchange

Abstract

Early observations and more recent systematic studies of solid-state ion exchange in zeolites, which is a possible way of zeolite modification, are reviewed. Particular attention is paid to the presentation of important experimental techniques which are appropriate to prove solid-state reaction in zeolites and determine the degree of such solid-state ion exchange. Examples are provided for the introduction of alkaline, alkaline earth, rare earth and transition metal cations into zeolites such as A, X, Y, mordenite and ZSM-5. Techniques of investigation are IR, ESR, MAS NMR, XRD, XPS, TPD and chemical analysis.