The diffusion mechanism of alkali metal ions in the particles of cerium(IV) antimonate

The kinetic behaviour of Li+, Na+, K+ and Cs+ ions exchange on cerium(IV) antimonate were investigated under conditions of particle diffusion and the limited batch technique. Values for the diffusion coefficients, activation energy and entropy of activation were calculated and their significance were discussed. The values of the effective diffusion coefficient increased in the order Cs+ > K+ > Na+ > Li+, which parallels the ionic radii and the ionic mobility. The activation energy (E(a)) was found to decrease with decreases in the entropy change of the system. The data obtained for this exchanger were compared with those for organic resins and other inorganic ion exchangers.