Exceptional CO2 Capture Capability and Molecular-Level Segregation in a Li-Modified Metal-Organic Framework

In this work, a computational study is performed on CO2 capture from various practical systems in a Li-modified metal organic framework (MOF), chem-4Li MOF. The results demonstrate that this material shows exceptional CO2 capture capability, due to the enhancement of the electrostatic potential in it by the presence of lithium. This study shows that not only the strength and gradient but also the distribution of the electrostatic potential can be controlled by metal doping, leading to more obvious heterogeneity in electrostatic potential in the material, resulting in the occurrence of molecular-level segregation for some systems. The present work observes for the first time that molecular-level segregation can occur in MOFs with simple cubic pores of different sizes and reveals that if the preferential adsorption sites of the less selective component can be shifted to its less preferential adsorption sites, the material may exhibit an exceptionally high selectivity, and such a shift can be achieved by various methods, for which metal doping is an effective way.