A robust metal-organic framework showing two distinct pores for effective separation of xenon and krypton

Abstract

For Xe/Kr adsorption-based separation, the current process was focused on cryogenic distillation, which is energy intensive. Metal-organic frameworks (MOFs), as an alternative solid state adsorbents, is highly interesting. Here, we reported a new robust MOF (ECUT-51) with two different sizes of pores (pore A and pore B). The excellent Xe/Kr separation ability was attested by dynamic breakthrough experiments. A deep insight into the separation mechanism was further obtained via Grand Canonical Monte Carlo (GCMC) simulation and Density Functional Theory (DFT) calculation. The theoretical calculations unveiled that both Xe and Kr can be accommodated in pore A, while Kr was prohibitive in pore B.