In situ NMR study of hydrothermal synthesis of a template-mediated microporous aluminophosphate material: AlPO4-CJ2

To elucidate the formation mechanisms of crystalline microporous materials prepared under hydrothermal conditions, one needs to observe the hydrothermal medium while the material forms. One of the main objectives is to investigate whether the condensed phase forms from the assembly of molecular precursors in solution or from a solid phase transformation. Therefore, in situ NMR was carried out to observe species present in solution. The study was applied to formation of an amine-mediated microporous oxyfluorinated aluminophosphate christened AlPO4-CJ2. In situ 31P, 14N, 27Al, and 19F, NMR study under hydrothermal conditions at 423K allowed us to follow pH evolution during the synthesis and to propose the structure of species in solution.