Investigation of crystallization of microporous materials by dry- gel conversion

摘要

The formation of aluminophosphate-based molecular sieves including AlPO_4-5 and AlPO_4-11 has been investigated by dry-del conversion (DGC) methods. For AlPO_4-5, under vapour-phase transport conditions several key reactive intermediates were captured and their structures characterized. A clear picture of the formation of AlPO_4-5 is presented. The crystallization under steam-assisted conversion conditions, however, follows a different pathway. Using AlPO_4-11 as an example, the involvement of water in vapour in DGC by solid-state ~(17)O NMR spectroscopy is demonstrated.