The density functional theory was used to study the adsorption sites, conformation and the adsorption energies of methane in MOF-5. The results show that there are four adsorption sites, and the Zn₄O clusters are the preferential adsorption sites, for which the adsorption energy is 17.38 kJ•mol^－1, larger than that in zeolites. This work shows that the adsorption energy around the aromatic rings can be increased by introducing electron-donor functional groups. In addition, the introduction of polar functional groups such as O containing groups to the organic linkers can introduce additional adsorption sites that increase methane adsorption capacity.

Key words: methane, metal-organic framework, adsorption, density functional theory