Location of cation sites in a hydrated copper-exchanged chabazite by extended X-ray absorption fine structure

Abstract

The local structure around copper ions in a hydrated copper-exchanged chabazite has been characterized by means of extended X-ray absorption fine structure spectroscopy. The model proposed on the basis of the experimental results indicates that copper ions occupy two sites, one with a distorted octahedral co-ordination, the other with a square-pyramidal geometry. The previously suggested hypothesis that copper ions are located in the large cavity of the chabazite is confirmed, although a different co-ordination for one site was detected.