Location of acid sites in natural and synthetic zeolites: diffractometric study of ammonia and hydrogen forms.

This work is part of a project whose purpose is to localize Brønsted and Lewis sites in natural and synthetic zeolites by diffractometric methods (X-ray and neutron diffraction, on single crystals and powders). Protons bonded to framework oxygens act as Brønsted sites on the catalytic properties of zeolites. The location of framework hydroxyls in hydrogen provides a basis for the interpretation of these properties. The aim of this work is to study not only hydrogen zeolites, but also their precursors obtained by cationic exchange with ammonia