Thermodynamic treatment of exchange of H+ and K+ in α-titanium phosphate
Abstract
The H+/K+ ion-exchange process in α-titanium phosphate, Ti(HPO4)2·H2O, was studied, titration curves and exchange isotherms being obtained at 25.0, 40.0, and 55.0 (± 0.1)°C. Partial decomposition of the exchanger was detected. No partially substituted phases were detected by X-ray diffraction and the final product was Ti(KPO4)2·3H2O. The free energy, enthalpy, and entropy for the exchange reaction are determined, and the results are explained by means of structural considerations.