To become a viable CO{sub 2} transport membrane, a reversible interaction between CO{sub 2} and the membrane material at the operating condition is a must. In the past quarter, we have conducted a comprehensive reversibility study using TGA and MS at {approx}200 C for both adsorption and desorption. This quarterly report summarizes the results. Evidently, CO{sub 2} can be reversible adsorbed and desorbed on the hydrotalcite surface via a pressure swing operation (i.e., between 1 bar and vacuum). About 2wt% working capacity was obtained. Even in the presence of water, the reversibility still holds. In the next quarter, we will focus on the reversibility under other operating conditions and the kinetic aspect of the reversibility study.