Synthesis and characterization of novel alumina-pillared gamma-zirconium phosphates

The preparation of alumina-pillared gamma -zirconium phosphate materials wa s carried out for the first time by thermal hydrotreatment at 473 K of stab le aqueous colloidal suspensions of gamma -zirconium phosphate and aluminum oligomeric solutions. The nature of the resulting porous materials depends on the delamination processes used. P-31 MAS NMR data suggest the existenc e of P-O-Al groups, and Al-27 NMR analysis by means of the two-dimensional five-quanta MQMAS technique reveals the coexistence, in some cases, of octa hedral, tetrahedral, and pentacoordinate aluminum. The samples, fresh and a fter heating at 673 K, were fully characterized by chemical analysis, X-ray diffraction analysis, thermogravimetric-differential thermal analysis, X-r ay photoelectron spectroscopy, temperature-programmed desorption of NH3, py ridine adsorption coupled to IR spectroscopy, and nitrogen adsorption-desor ption at 77 K.