SYNTHESIS AND CHARACTERIZATION OF A FAMILY OF AMINE-INTERCATALATED LAMELLAR ALUMINOPHOSPHATES FROM ALCOHOLIC SYSTEM

A family of lamellar aluminophosphates designated APO-Ln (L stands for lamellar and n = 6, 8, 10, 12, the number of carbon atoms for the occ luded template molecules) was synthesized from a mixture of phosphoric acid, aluminum triisopropoxide, ethylene glycol and an unbranched pri mary alcohol in the presence of an amine as the structure-directing te mplate. The compounds were characterized by X-ray powder diffraction, scanning electron microscopy, MAS NMR spectroscopy, differential therm al, and thermogravimetric analyses. The inorganic layers of APO-Ln are composed of PO4, AlO4, and AlO6 structural units, and the ratio of th e octahedral Al to the tetrahedral Al in the as-synthesized compounds is about 1:1. APO-Ln exhibit a distinct weight loss when treated at el evated temperatures, and upon dehydration they adsorb a considerable a mount of water. Dehydration-rehydration for APO-Ln materials is revers ible with the dehydrated samples containing almost only tetrahedrally coordinated aluminum.