Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

A model of CoO oxidation was proposed which assumes the diffusion of cobalt atoms from the bulk of crystalline to its surface and the surface reaction of these atoms with surrounding oxygen. It depends on the comparison of expressions D/a²₀ and kx_ox/a₀ to what extent these two processes will manifest themselves for the given temperature and oxygen mole fraction x_ox. The value of diffusivity D and its temperature dependence were estimated from the data in literature and the size of crystallites a₀ from roentgenographic measurements. The value of rate constant of surface reaction k and its energy of activation were evaluated from experimental data for CoO oxidation.