Low temperature mechanism of adsorption of methane: Comparison between homogenous and heterogeneous pores

作者：Dundar Ege; Rogack Justyna; Firlej Lucyna; Wexler Carlos; Llewellyn Philip; Boulet Pascal; Kuchta Bogdan^*

来源：Colloids and Surfaces A: Physicochemical and Engineering Aspects , 2016, 496: 86-93.

DOI：10.1016/j.colsurfa.2015.11.063

• Methane adsorption
• Slit pores
• IRMOF-1
• IRMOF-16
• Heterogeneity

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.

• 出版日期2016-5-5