Experimental and statistical modeling study of low coverage gas adsorption of light alkanes on meso-microporous silica

Adsorption properties of linear and branched (C5–C9) alkanes were studied on the mesoporous materials MCM-41, MCM-48, PHTS and SBA-15 in the 75–195 °C temperature range. Adsorption enthalpies at zero coverage and Henry constants were measured by gas phase chromatography. The experimental data was statistically investigated and used for modeling. Quantitative structure activity/property relation models were established relating structural descriptors of adsorbate and adsorbent to adsorption properties using partial least square regression. It was shown that the presence of micropores leads to an increase in Henry constants and adsorption enthalpies but does not induce shape selectivity. Excellent agreement is found between experimental and modeled adsorption properties. In depth analysis reveals influence of the degree of branching but not the position of the branching for these materials.

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► Experimental adsorption properties of alkanes on 4 mesoporous silica materials.
► Influence of micropores on the adsorption properties is demonstrated.
► Quantitative structure–property relationship models for multiple adsorbents.
► Predictive accuracy within the experimental error using topological descriptors.