Statistical molecular calculation of thermodynamic parameters of adsorption of aromatic hydrocarbons on graphite. Part 1.—Condensed aromatic hydrocarbons

Abstract

A statistical molecular calculation is carried out of the Henry constant, K₁, and of the differential changes in internal energy, ΔU₁, and heat capacity, ΔC₁, for the adsorption of benzene and some aromatic hydrocarbons with condensed nuclei on the basal plane of graphite at zero surface coverage. It is shown that the atom–atom approximation is applicable in the case of intermolecular interactions between the simplest condensed aromatic hydrocarbons and graphite. The intermolecular interaction of the C atom in graphite with the C atom of the aromatic ring is close to that of C atoms forming a double bond in alkenes. This interaction is ≈ 7% greater than that of the C atom in graphite with the C atom of alkanes. The small difference between the thermodynamic parameters of adsorption of anthracene and phenanthrene is mainly connected with the difference in the electronic configuration (polarizability) of the molecules.