The ion-exchange capacity of Ti and Zr lamellar hydrogenphosphates - TG measurements

Thermogravimetric data were used to calculate the number of acidic Bronsted sites in lamellar alpha-titanium (alpha-TiP), gamma-titanium (gamma-TiP), alpha-zirconium (alpha-ZrP) and gamma-zirconium (gamma-ZrP) hydrogenphospha tes. The numbers of acidic sites calculated for these lamellar compounds we re 7.81, 5.67, 6.33 and 5.56 for alpha-TiP, gamma-TiP, alpha-ZrP and gamma- ZrP, respectively. These values are in good agreement with those found thro ugh potentiometric titration. The data obtained prove that thermogravimetri c measurements can be used as a reliable analytical tool to follow the ion- exchange capacity of this kind of crystalline lamellar compounds.