AlPO4-41 aluminophosphate molecular sieve:: a new reproducible synthesis route involving diisopropylformamide as template precursor

Until now, pure AlPO4-41 aluminophosphate was difficult to synthesize, the product being often admired with other microporous solids, such as AlPO4-11 and/or AlPO4-31. In this study, we propose a new reproducible synthesis route of AlPO4-41. Nevertheless, some traces of an aluminophosphate hydrate, which decompose at 200 degrees C co-crystallize. The AFO-type aluminophosphate is obtained From a quasi-non-aqueous system involving diisopropylformamide (DiPF) as solvent in addition to restricted amounts of water. During the synthesis, DiPF is decomposed into carbon monoxide and diisopropylamine. The latter is occluded into the AlPO4-41 framework and acts as a template as the crystallization proceeds. The slow and in situ release of the amine in the reaction batch is a key factor for the formation of the AFO-type material. The as-synthesized AlPO4-41 is characterized by chemical bulk analysis, XRD and solid state C-13 CP MAS NMR spectroscopy. (C) 2000 Elsevier Science B.V. All rights reserved.