Computer-aided design of high-connectivity covalent organic frameworks as CH4/H2 adsorption and separation media

Six novel borophosphonate cube (–B4P4O12–) based covalent organic frameworks (BP-COFs) with high-connectivity have been computationally designed and proposed as CH4/H2 adsorption and separation media. The structural characterization reflects that six BP-COFs own high porosity, low density, applicable pore size, large pore volume and accessible surface area which are beneficial to gas adsorption. The adsorption isotherms for H2 at 77 K and 298 K and for CH4 at 298 K were obtained with grand canonical Monte Carlo (GCMC) simulations. The results reveal that BP-COF-10, -11 and −12 possess the higher CH4 and H2 adsorption capacity versus BP-COF-7, -8 and -9. The CH4/H2 adsorption separation simulation indicated that BP-COF-7, -8 and -9 owns the better CH4/H2 selectivity than BP-COF-10, -11 and −12 at 298 K. It is excited that both CH4/H2 adsorption capacity and selectivity of six BP-COFs are comparable to porous materials owing excellent gas adsorption and separation capacity. We expect this study may motivate researchers’ efforts to develop new high-performance gas adsorption/separation material.