Methane adsorption in several series of newly synthesised metal-organic frameworks: a molecular simulation study

In this work, the adsorption of methane in several newly synthesised metal-organic frameworks (MOFs) is studied using grand canonical Monte Carlo simulations. The factors influencing the adsorption behaviour of methane in different series of materials were investigated at low, moderate and high pressures, respectively. The simulation results show that the isosteric heat of adsorption at infinite dilute, the accessible surface area and the free volume of materials play important roles in methane adsorption, while the main factors are different in different ranges of pressure. These are consistent with the rules obtained from well-studied MOFs by the Snurr group and by Wang, proving that they are applicable to the newly synthesised MOFs. Based on these, the influencing factors were further discussed by classifying the MOFs through the pore topology, and it was found that the pore topology should not be ignored when performing efficient modifications of MOFs at moderate and high pressures. This work may provide useful information to design novel MOFs with high methane uptake in the future.