Stable and recyclable CO2 adsorption at room temperature with monoethanolamine-functionalized montmorillonite

The clay mineral-based composite was explored for adsorption of CO 2 , which was fabricated by impregnating monoethanolamine (MEA) on montmorillonite (Mont). The hydroxyl groups of Mont removed, and was found to be only physical loaded-amines after thermal treatment (T-Mont). The MEA molecules were well combined with the -OH surface of Mont, which enhanced stability and cyclability for CO 2 adsorption. The composite 40-MEA@Mont displayed excellent adsorption performance, and adsorption capacity reached 8.72 cm 3 ∙g −1 at room temperature. After eight cycles of CO 2 adsorption, the capacity of 40-MEA@Mont showed no noticeable changes compared to the first cycle, whereas 40-MEA@T-Mont was 15.19 % decline. The reason lies in the hydrogen bond interaction between amine and Mont matrix which was further confirmed by DFT calculation. Isosteric heat of adsorption analysis and in situ FT-IR manifested that CO 2 adsorption predominantly involved weak chemisorption on the composite 40-MEA@Mont. The CO 2 adsorption mechanisms of clay-based support can be controlled by adjusting the type of impregnated amines, and the layered montmorillonite loaded with amines can be a promising material for CO 2 adsorption at room temperature.