Lamellar and hexagonal mesostructured aluminophosphates (AlPOs) were prepared and characterized. The lamellar mesostructured AlPO (APW-1) formed hydrothermally and the condensed framework was composed of alternating AlO 4 and PO 4 units. The hexagonal mesostructured AlPO (APW-2) is formed by transformation of a layered precipitate composed of both aluminophosphate oligomers and alkyltrimethylammonium (ATMA) cations. Calcined APW-2 had a mesoporosity with the BET surface area of 980 m 2 g - 1 and a pore diameter of 1.8 nm after substantial shrinkage of the framework. Lamellar APW-1 formed under most of the conditions surveyed, while hexagonal APW-2 was obtained under very restricted conditions. In this system, the charge matching in the products is the most important factor, although the assemblies of ATMA cations are essential as the structure-directing agents.
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Kimura et al. (1999) studied this question.
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