High CO sub(2) Chemisorption in alpha -Li sub(5)AlO sub(4) at Low Temperatures (30-80 degree C): Effect of the Water Vapor Addition

alpha -Li sub(5)AlO sub(4) was synthesized using a solid-state reaction, and then different water sorption experiments were performed using N sub(2) and CO sub(2) as carrier gases. When the N sub(2)-H sub(2)O flow gas was used, alpha -Li sub(5)AlO sub(4) showed a water vapor sorption because of two different processes: superficial hydration and hydroxylation. However, if CO sub(2) was used as the water vapor carrier gas, the alpha -Li sub(5)AlO sub(4) carbonation process was observed at low temperatures (30-80 degree C), although this reaction is only produced at high temperatures (200-700 degree C) under dry conditions. In this case, the carbonation process was induced by the lithium ceramic superficial hydroxylation. The results clearly showed that alpha -Li sub(5)AlO sub(4) is capable of chemisorbing up to 8.4 mmol of CO sub(2)/g of ceramic, a considerably high capture at low temperatures compared to different materials. Finally, a kinetic analysis indicated that the CO sub(2) chemisorption in alpha -Li sub(5)AlO sub(4) is highly favored in the presence of water vapor.