Hydrothermal synthesis and characterisation of crystalline sodium zirconium phosphates

Abstract

Sodium zirconium phosphates have been synthesised hydrothermally in the presence of triethylamine, aiming at the formation of zeolite type porous crystalline sodium zirconium phosphates. The materials have been characterised by X-ray and electron diffraction, electron microscopy, thermal analysis, framework IR and 31P MASNMR spectroscopies and adsorption techniques. The compounds are monoclinic, with lattice parameters, a = 15.29 Å, b = 8.80 Å, c = 18.26 Å, and β = 123°. 31P MASNMR spectra of this compound exhibited three distinct resonances at d= −8.4, −20.1 and −24.5 ppm respectively corresponding to three crystallographically nonequivalent positions for the phosphorus atoms. The materials were microporous and adsorbed significant amounts of water, n-hexane, benzene, m-xylene, cumene, tetrabutylamine and 1,3,5 trimethyl benzene.