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 simu-lation 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 separa-tion capacity. We expect this study may motivate researchers' efforts to develop new high-performance gas adsorption/separation material. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Six novel borophosphonate cube (BP-COFs) based covalent organic frameworks with high-connectivity were computationally designed for CH4/H2 adsorption and separation. The structural characterization showed that these BP-COFs possess high porosity, low density, suitable pore size, large pore volume, and accessible surface area, which are beneficial for gas adsorption. The simulation results revealed that BP-COF-10, -11, and -12 had higher CH4 and H2 adsorption capacity compared to BP-COF-7, -8, and -9. The CH4/H2 adsorption separation simulation indicated that BP-COF-7, -8, and -9 exhibited better CH4/H2 selectivity at 298 K. The excellent gas adsorption and separation capacity of these BP-COFs suggest their potential as high-performance gas adsorption/separation materials.