From Porous Metal Phosphates to Oxophenylphosphates: A Review

In the following review article we have given a brief overview about the synthesis, characterization and potential applications of various organically modified phosphate-based molecular sieves, metal-oxophenylphosphates and the patent literature of this field (since its discovery). These include the oxophenylphosphates of tin, titanium, niobium, iron, tantalum, calcium and zirconium. The characterization of the materials has been discussed in details, which includes nanostructure elucidation using powder X-ray diffraction, nitrogen adsorption/desorption, transmission and scanning electron microscopic studies, spectroscopic analysis using FT-IR, UV-Visible, 13C and 31P MAS NMR, XPS, and thermal analysis. These materials find potential applications in adsorption, shape-selective acid-base catalysis and can be used as membrane, support for anode and cathode material in fuel cell. The sulfonated materials derived from these hybrids show high Bronsted acidity, proton conductivity and selectivity for a number of acid catalyzed organic transformations.