Synthesis of Mesostructured Lamellar Aluminophosphates Using Supramolecular Templates

Abstract

The liquid-crystal templating approach for the synthesis of mesostructured materials was extended to aluminophosphates. A variety of lamellar AlPO4 phases with d spacings in the nanometer range were prepared in the presence of long-chain primary and tertiary amines. A systematic study of the influence of the gel composition was carried out. AlPO4 materials were characterized by various techniques including XRD, TEM, electron diffraction, and 27Al, 31P, 15N, and 13C NMR. The gel composition has a drastic influence on the nature of the product formed and on the coordination of aluminum and phosphorus in the final “crystalline” phase. These lamellar AlPO4 phases were not stable under calcination conditions and the templating surfactant could not be removed by solvent extraction.