Molecular mechanism of hydrocarbons binding to the metal-organic framework

► Molecular dynamics simulations were carried out to investigate the adsorption and diffusivity of alkane molecules in a MOF. ► According to the RDFs of n-hexane and cyclohexane with zinc in the MOF, with a flexible and linear structure, the n-hexane molecules can sample more phase space than cyclohexane molecules. ► Free energy decreases with increasing carbon chain length, and the adsorption enthalpy and entropy contain a linear relationship with respect to the number of carbons in the molecules, but enthalpy has a more negative slope than entropy times temperature.