MODELIZATION OF SAPO–37 AND ITS VERIFICATION THROUGH PHYSICOCHEMICAL CHARACTERIZATION AND CHEMICAL REACTIVITY

A topological model for SAPO–37 which includes up to the third coordination sphere, and which fits reported atom distributions has been developed. The model predicts a low proportion of AI(4Si0P) groups, and therefore no large zeolitic domains in SAPO–37 are expected. However, it is shown that samples with the same chemical composition present different framework atom distributions depending on the synthesis procedure. SAPO–37 with different Si content show weaker acidity than USY zeolites; the former being more active for less acid demanding reactions, and less active for reactions needing strong acid sites.