Effect of rare earth oxides on the thermal decomposition of barium oxalate

Abstract

Catalytic activity of rare earth oxides (REO); La2O3, Sm2O3, Gd2O3 and Ce2O3 on the isothermal decomposition of barium oxalate has been studied at 723 K. The α−t plots for pure salt as well as mixtures indicate that the process follows: initial gas evolution, a short acceleratory and a long decay stages. The results of the kinetic analysis show that Prout-Tompkins relationship and two-dimensional phase boundary reaction give best fit of the data for both pure salt as well as mixtures. The rate constants of acceleratory and decay periods are enhanced remarkably by adding REO admixtures and their catalytical activity is in the order La2O3>Sm2O3>Gd2O3 >Ce2O3. The plausible mechanism of decomposition and the role of admixture there on has been discussed in the light of electron transfer process.