Synthesis of new aluminophosphate materials with the FAU and AFR structure-types

Abstract

The modification of the synthesis procedure used for the crystallization of SAPO-37 (FAU-type), namely an addition of a source of a divalent element Me like Zn or Co in place of, or in addition to silica, a small decrease in the pH and a decrease in the crystallization temperature, allowed new MeAPO- and MeAPSO-FAU materials to be obtained. Moreover, a higher water content of the gel allowed the tetramethylammonium cation content to be increased and therefore to be closer to the stoichiometric amount. Further, in spite of the presence of tetrapropyl- and tetramethylammonium cations which are specific templates for the FAU-type structure, the synthesis conditions could also be adapted to obtain, but with more difficulty, the new MeAPO- and MeAPSO-AFR-type materials. It should be noted that in the absence of Me elements the AlPO₄-AFR-type phase formed very easily which is not the case for the AlPO₄-FAU-type phase.