Ion exchange of synthetic zeolite A with Cr(III) ions

Abstract

A series of chromium-exchanged zeolite A was prepared by ion-exchange using very dilute solution of a chromium(III) salt. The chromium(III) ions can replace up to 40% sodium cations. A significant lattice decomposition was found at higher chromium exchange levels. Chemical, X-ray diffraction, and thermal analyses were made and data on the composition and the unit cell dimensions are reported. The diffuse reflectance spectra of the as-made and the dehydrated chromium-exchanged zeolite A were investigated. In the as-made product chromium(III) is octahedrally coordinated whereas after dehydration its coordination number decreases.