Sc-functionalized porphyrin-like porous fullerene for CO₂ storage and separation: A first-principles evaluation

In recent years, there has been a lot of interest in capturing and storing carbon dioxide (CO₂) on porous materials as an efficient method for decreasing the adverse effects of this greenhouse gas on the environment and climate change. The current work introduces a Sc-decorated porphyrin-like porous fullerene (Sc₆@C₂₄N₂₄) as an efficient material for CO₂ capture, storage, and separation using density functional theory calculations. While CO₂ is physisorbed over pristine C₂₄N₂₄, the addition of Sc atoms on the N₄ sites of C₂₄N₂₄ greatly enhances CO₂ adsorption energy. Each Sc atom in Sc₆@C₂₄N₂₄ may adsorb up to three CO₂ molecules, resulting in a gravimetric density of 48%. Moreover, temperature may be used to modulate CO₂ adsorption/desorption over the substrate. The Sc-decorated C₂₄N₂₄ fullerene exhibits a lower affinity for adsorbing N₂, CH₄, and H₂ molecules than CO₂. As a consequence, this material might be considered for purifying CO₂ molecules from CO₂/N₂, CO₂/CH₄, and CO₂/H₂ mixtures. This study also sheds light on the nature of the Sc-CO₂ interaction as well as the underlying mechanism of selective CO₂ adsorption on Sc decorated C₂₄N₂₄.