Porous fluorinated aluminum and mixed gallium/aluminum oxide pillared tin phosphate materials with acid properties

Fluorinated aluminum and mixed gallium/aluminum oligomers of high nuclearity have been intercalated into cr-tin phosphate by refluxing fluorinated Al and mixed Ga/Al oligomeric solutions in the presence of colloidal tin phosphate. P-31 and Al-27 MAS NMR spectroscopy has revealed the existence of strong interactions between the phosphate layers and the oligomeric guest species, conferring to these expanded materials a high thermal stability, as confirmed by XRD studies. Formation of Al and mixed Ga/Al oxide nanoparticle pillars in the interlayer region of tin phosphate, upon calcination at 400 degrees C, gave rise to porous materials with specific surface areas between 160 and 304 m(2) g(-1) and micropore volumes close to 0.1 cm(3) g(-1). The pillared materials are highly acidic solids and behave as dehydrating catalysts for the decomposition reaction of isopropyl alcohol. The Lewis acid sites, believed to be mainly responsible for the catalytic activity, are associated with low coordination sites of Al ions present in the interlayer oxide pillars.