High CO2Chemisorption in α-Li5AlO4at Low Temperatures (30–80 °C): Effect of the Water Vapor Addition

Abstract

α-Li5AlO4 was synthesized using a solid-state reaction, and then different water sorption experiments were performed using N2 and CO2 as carrier gases. When the N2–H2O flow gas was used, α-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 α-Li5AlO4 carbonation process was observed at low temperatures (30–80 °C), although this reaction is only produced at high temperatures (200–700 °C) under dry conditions. In this case, the carbonation process was induced by the lithium ceramic superficial hydroxylation. The results clearly showed that α-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 α-Li5AlO4 is highly favored in the presence of water vapor.