Modelling CO2 adsorption and separation on experimentally-realized B40 fullerene

Searching for efficient solid sorbents for CO2 adsorption and separation is important for developing emergent carbon reduction and natural gas purification technology. This work, for the first time, has investigated the adsorption of CO2 on newly experimentally realized cage-like B-40 fullerene (Zhai et al., 2014) based on density functional theory calculations. We find that the adsorption of CO2 on B-40 fullerene involves a relatively large energy barrier (1.21 eV), however this can be greatly decreased to 0.35 eV by introducing an extra electron. A practical way to realize negatively charged B-40 fullerene is then proposed by encapsulating a Li atom into the B40 fullerene (Li@B-40). Li@B-40 is found to be highly stable and can significantly enhance both the thermodynamics and kinetics of CO2 adsorption, while the adsorptions of N-2, CH4 and H-2 on the Li@B40 fullerene remain weak in comparison. Since B-40 fullerene has been successfully synthesized in a most recent experiment, our results highlight a new promising material for CO2 capture and separation for future experimental validation. (C) 2015 Elsevier B.V. All rights reserved.