γ-zirconium and γ-titanium phosphates platinum intercalation compound -: Preparation, characterization and thermal behaviour

Inorganic ion-exchangers with a layered structure such as gamma-zirconium and gamma-titanium phosphates, intercalated with organic diamines, are able to exchange Pt2+ ions to give new intercalation compounds that can be utilized in heterogeneous catalysis. The experiments performed at different temperatures (25 and 45 degrees C), show different ion uptakes, greater at 45 degrees C and for the materials derived from gamma-zirconium phosphate. After platinum exchange, all the materials show an amorphization in the XRD if compared with their precursors. The thermal behaviour of the platinum materials is specific, depending on the exchanger used and the ligand inside the exchanger. Pt2+ ion has a catalytic effect on ligand elimination in the gamma-zirconium phosphate platinum compounds, but not in those derived from gamma-titanium. All the obtained yellow materials show a small step in the TG curves and simultaneously we have the Pt2+-->Pt-0 reduction: this is confirmed by XRD registered at the temperatures of the thermal effect, showing peaks at d(hkl)=2.27 and 1.95 Angstrom.