Low temperature mechanism of adsorption of methane: Comparison between homogenous and heterogeneous pores Auteur(s): Dundar Ege, Rogacka J., Firlej L., Wexler Carlos, Llewellyn Philip, Boulet Pascal, Kuchta Bogdan (Article) Publié: Colloids And Surfaces A: Physicochemical And Engineering Aspects, vol. 496 p.86-93 (2016) Texte intégral en Openaccess : Ref HAL: hal-01477924_v1 DOI: 10.1016/j.colsurfa.2015.11.063 WoS: 000372878600010 Exporter : BibTex | endNote 6 Citations Résumé: ! abstract The mechanisms of methane adsorption in (i) homogeneous carbon slit pores of widths between 1 nm and 2 nm and (ii) heterogeneous MOF pores of similar unit cell sizes have been compared. We discuss the mechanism of layering transition in subcritical conditions, for temperatures between 80 K and 180 K. The layer formation is strongly temperature-dependent. In slit pores it varies from a sharp adsorption at low temperatures to a more continuous uptake at higher temperatures. The pore size defines the number of adsorbed layers: the 1 nm pore allows adsorption of 2 layers while the 2 nm pore allows adsorption of 5 layers of methane molecules. We compare this behavior with the mechanism of adsorption in two MOFs, IRMOF-1 and IRMOF-16, with strongly heterogeneous walls (both structurally and energetically). This comparison allows us to discuss separately the influence of wall topology and intermolecular interactions on the mechanism of layering. |