Computational screening of porous coordination networks for adsorption and membrane-based gas separations

Abstract

Porous coordination networks (PCNs) are promising nanoporous materials in gas separation applications due to their tunable pore sizes, large surface areas, high porosities, and good thermal and mechanical stabilities. In this work, we investigated adsorption-based and membrane-based separation performances of 20 different PCNs for CH4/H-2, CO2/H-2, CO2/CH4, and CO2/N-2 mixtures using molecular simulations. Several PCNs were identified to show higher selectivity than traditional zeolites and polymers in membrane-based CO2 separations. We also developed simple models that can predict adsorption, diffusion, and permeation selectivities of PCNs for CH4/H-2 and CO2/H-2 mixtures based on the structural properties of materials such as pore volume, surface area, and pore diameter.