Hydrolysis of europium cations in zeolite X: A fourier transform infrared spectroscopic study

A series of thermally activated europium-exchanged X zeolites with comparable cation loadings have been characterized by infrared spectroscopy. The distribution of surface hydroxyl species observed following sample dehydration was found to be influenced by the preparation conditions employed during ion exchange, and increasing time of contact between the exchange solution and the parent NaX sample resulted in an increase in the abundance of surface hydroxyl groups. On the basis of the observed infrared data, it is proposed that the surface hydroxyl species arise as a consequence of hydrolytic reactions occurring within the zeolite cages during ion exchange and not as a consequence of thermally promoted hydrolysis