Lithium zirconate doped with potassium (K-Li2ZrO3) was synthesized by solid-state reaction and then its CO2 chemisorption capacity was evaluated using different CO2-O-2 gas mixtures. These experiments were performed in order to evaluate the effect produced by the O-2 on the kinetic parameters and on the CO2 absorption reaction mechanism. Although the CO2 capture dynamic experiments did not show significant variations as a function of the O-2 content, isothermal experiments and their fining to the Eyring's model did. Different enthalpy activation (Delta H double dagger) values were estimated for the CO2 chemisorption process, as CO2 capture is produced by two processes: Initially, the CO2 chemisorption occurs directly over the K-Li2ZrO3 surface. Then, once a Li2CO3-ZrO2 external shell is produced, CO2 chemisorption is kinetically controlled by diffusion processes, which must imply the lithium and oxygen diffusion. The Delta H double dagger values, of the CO2 direct chemisorption, increased as a function of the O-2 content. It was explained in terms of a CO2-O-2 competition to occupy the Li2ZrO3 surface. On the other hand, the Delta H double dagger values, of the CO2 chemisorption kinetically controlled by diffusion processes, decreased as a function of the O-2 content. This result confirmed the oxygen diffusion dependency of the CO2 chemisorption on lithium zirconate.