High CO2 Chemisorption in α-Li5AlO4 at Low Temperatures (30-80 °C): Effect of the Water Vapor Addition

alpha-Li5AlO4 was synthesized using a solid-state reaction, and then different water sorption experiments were performed using N-2 and CO2 as carrier gases. When the N-2-H2O flow gas was used, alpha-Li5AlO4 showed a water vapor sorption because of two different processes: superficial hydration and hydroxylation. However, if CO2 was used as the water vapor carrier gas, the alpha-Li5AlO4 carbonation process was observed at low temperatures (30-80 degrees C), although this reaction is only produced at high temperatures (200-700 degrees C) under dry conditions. In this case, the carbonation process was induced by the lithium ceramic superficial hydroxylation. The results clearly showed that alpha-Li5AlO4 is capable of chemisorbing up to 8.4 mmol of CO2/g of ceramic, a considerably high capture at low temperatures compared to different materials. Finally, a kinetic analysis indicated that the CO2 chemisorption in alpha-Li5AlO4 is highly favored in the presence of water vapor.