γ-Zirconium Phosphate Rhodium Intercalation Compounds: Preparation, Chemical and Thermal Characterization

Rh3+/H+ ion exchange in γ-zirconium phosphate and in its intercalation compounds with organic diamine (2,2′-bipyridyl, 1,10-phenanthroline, and 2,9-dimethyl-1,10-phenanthroline) has been investigated. Fully exchanged rhodium-zirconium phosphate has the composition γ-Zr(PO4)(H0.86Rh0.38PO4)·2.3H2O and an interlayer distance of 15.2 Å. The exchange of Rh3+ in intercalation compounds leads to phases in which the molar ratio Rh3+/diamine within the layers is about one. In some cases, a partial leaching of organic ligand during the Rh3+/H+ exchange has been observed. All the materials produced were characterized by their chemical compositions, X-ray powder diffraction patterns, and coupled TG/DTA analysis. In the presence of Rh3+ ions, the temperature of thermal deintercalation of diamine is lower than that observed in the pure intercalation compounds.