Theoretical simulation of CO₂ capture in organic cage impregnated with polyoxometalates

To explore the adsorption and separation properties of CO₂ in a novel material consisting of a series of polyoxometalates (POMs) impregnated within supramolecular porous catenane (shorted as SPC), grand canonical Monte Carlo (GCMC) simulations and ab initio calculations were used. GCMC simulations showed this impregnation can enhance CO₂ /CH₄ (or CO₂ /N₂ ) selectivity almost 30 times compared to the bare SPC due to the strong interaction of CO₂ with the nPOMs@SPC structures. And, the loading of CO₂ inhibits the adsorption of CH₄ (or N₂ ) as CO₂ occupying the preferred adsorption sites. Furthermore, the effect of number, mass, and volume of POMs inserted in SPC on CO₂ /CH₄ (or CO₂ /N₂ ) selectivity over large pressure range was investigated in detail. Additionally, the accurate ab initio calculations further confirmed our GCMC simulations. As a result, the proposed nPOMs@SPC structures are promising candidates for CO₂ /N₂ and CO₂ /CH₄ separations. © 2017 Wiley Periodicals, Inc.