Interrelations between Adsorption Energies and Local Isotherms, Local Monolayer Capacities, and Energy Distribution Functions, as Determined for Heterogeneous Surfaces by Inverse Gas Chromatography

Abstract

Physicochemical parameters for adsorption of gases at the submonolayer regions of heterogeneous solid surfaces are measured experimentally as a function of time, and then interrelated as local isotherms θ against adsorption energy ε, fractional changes of adsorption sites f(ε)/c*max against ε, θ against f(ε)/c*max, and distribution functions θ f(ε)/c*max over adsorption energy values ε, without using at all the well-known integral equation Θ(p, T)=∫∞0θ(p, T, ε)f(ε)dε and assumptions concerning the pair f(ε) and θ(p, T, ε). The method uses only chromatographic experimental data obtained by the inverse gas chromatography technique known as reversed-flow gas chromatography. It has been applied to the adsorption of cis-2-butene and trans-2-butene onto particles of Penteli marble at temperatures of 302, 314, 323, and 333 K. The results obtained are comparable with those calculated on the basis of the well-known integral equation.