Evolutionary model for computation of pore-size distribution in microporous solids of cylindrical pore structure

Three major contributions are recognized concerning the application of the Horváth–Kawazoe theory for calculation of pore-size distribution in cylindrical geometry. The shortcomings and merits of these models are pointed out. The drawbacks in the old equations are removed in our formulation benefiting from all capabilities of the reviewed contributions. The potential energies calculated by Rege and Yang are extended to cover all interlayer and intra-layer interactions while the energy gaps appeared in the new discrete formulation are vanished by translation of the discrete model into an integral-form equation as given by Saito and Foley. The pore-filling correction term introduced by Cheng and Yang is also incorporated, but a straight evaluation of the term via numerical solution is raised in place of the original postulation of the Langmuir equation to fit the isotherm data. The fidelity of the model is explored in application to several molecular sieves. The cavity sizes calculated by the new model are found to be in excellent agreement with those obtained from crystallographic analysis.

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► An integral population-averaged pore model is presented.
► All interlayer and intra-layer interactions are included.
► The discontinuity of the energy profile is addressed and eliminated.
► The pore-filling term is reformulated to cover all types of isotherm.
► The model improved the reliability of the cavity size and the quality of the PSD.