ИСТИНА

Hydrothermal synthesis is the main synthetic route leading to wide variety of materials such as zeolites, zeotypes, mesoporous and micro-mesoporous materials, hybrid inorganic-organic frameworks and other types of solids used for adsorption, catalysis, separation and etc. In this work we present a first study of zeolite material formation under hydrothermal condition by MAS NMR in situ approach. Five different stages of zeolite BEA formation were revealed during the synthesis. (1) Condensation of amorphous aluminosilicate enriched by aluminum. (2) Incorporation of TEA+ ions into amorphous aluminosilicate and its coordination with Al. (3) Proto-zeolite formation. (4) Transformation of proto-zeolite particles into BEA nuclei and (5) crystallization of bulk BEA zeolite. The role of different components in reaction gel and the contribution of “solid-solid” and “solution mediated” mechanisms at different stages of the process were established.