Buckybowls as adsorbents for CO2, CH4, and C2H2: Binding and structural insights from computational study

Noncovalent functionalization of buckybowls sumanene (S), corannulene (R), and coronene (C) with greenhouse gases (GGs) such as CO2, CH4 (M), and C2H2 (A) has been studied using hybrid density functional theory. The propensity and preferences of these small molecules to interact with the concave and convex surfaces of the buckybowls has been quantitatively estimated. The results indicate that curvature plays a significant role in the adsorption of these small molecules on the π surface and it is observed that buckybowls have higher binding energies (BEs) compared with their planar counterpart coronene. The concave surface of the buckybowl is found to be more feasible for adsorption of small molecules. BEs of small molecules towards π systems is CO2 > A > M and the BEs of π systems toward small molecules is S > R > C. Obviously, the binding preference is dictated by the way in which various noncovalent interactions, such as π···π, lone pair···π, and CH···π manifest themselves on carbaneous surfaces. To delineate the intricate details of the interactions, we have employed Bader's quantum theory of atoms in molecule and localized molecular orbital energy decomposition analysis (LMO‐EDA). LMO‐EDA, which measures the contribution of various components and traces the physical origin of the interactions, indicates that the complexes are stabilized largely by dispersion interactions. © 2015 Wiley Periodicals, Inc. Computational studies reveal that monolayer carbonaceous surfaces, such as sumanene, corannulene and coronene, are optimal for adsorption of small gas molecules such as CO2, CH4 and C2H2. The concave surface of the buckybowl is preferred over the convex alternative for the adsorption as well as the selective binding of small molecules. Dispersion is largely responsible for binding of small molecules, buckybowls and coronene.