Experimental Study and Atomic Level Description of Adsorption Process of CO₂ on Doped Alkaline Earth Oxides

Abstract

To realize CO₂ capture and storage, many methods for CO₂ sequestration should be investigated from a long-term viewpoint. The development of novel CO₂ absorbent material is considered to be a candidate for the effective CO₂ sequestration. Investigation of CO₂ absorbent material is usually based on the experiment with following thermodynamic analysis of obtained data. Recently, the introduction of large-scale simulation based on modern computational chemistry methods is found to be a powerful approach in order to explain and understand the experimental data. In the present study, the experimental measurements and ab-initio calculations were employed for studying the adsorption process of CO₂ on both clean and doped CaO (001) surface. The effect of addition of other alkaline earth metal oxide to CaO on adsorption energy of CO₂ was analyzed in detail. The relationship between the standard free energy change of carbonation of added alkaline earth metal oxide and extent of variation in the adsorption energy was not clear. However, the structural deformation of CaO surface caused by formation of compound or solid solution would vary the adsorption energy and in the case of CaO/BeO, it leads to significantly improve the capture of carbon dioxide during the first step of adsorption process. Reactivity of CaO with CO₂ was investigated by experimental. The experimental results agree with calculation result. Atomistic level description of adsorption process of CO₂ on the doped alkaline earth oxides was successfully carried out by ab-initio calculations.