Quantitative analysis of liquid-phase adsorption over chromium-containing metal–organic frameworks of MTN topology

• Published in: Adsorption : journal of the International Adsorption Society 2021-08, Vol.27 (6), p.953-962
• Main Authors: Brazhnik, Daria V., Skobelev, Igor Y., Kovalenko, Konstantin A., Kholdeeva, Oxana A.
• Format: Article
• Language: English
• Subjects: Adsorption; Affinity; Butanol; Chemical equilibrium; Chemistry; Chemistry and Materials Science; Chromium; Cyclohexanone; Engineering Thermodynamics; Equilibrium; Heat and Mass Transfer; Hexanes; Industrial Chemistry/Chemical Engineering; Liquid phases; Metal-organic frameworks; Quantitative analysis; Room temperature; Surfaces and Interfaces; Thin Films; Topology; Uranium
• ISSN: 0929-5607; 1572-8757
• DOI: 10.1007/s10450-020-00287-4

Excess adsorption of cyclohexanone, cyclohexanol and tert -butanol over metal–organic frameworks Cr-MIL-100 and structurally close Cr-MIL-101 from n -hexane was measured at room temperature. Apparent adsorption equilibrium constants were calculated under the assumption of monolayer adsorption. Two types of adsorption centers turned out to be enough to build a model of experimental isotherms for cyclohexanone, cyclohexanol, and tert -butanol. The first type of centers is characterized by a high value of adsorption equilibrium constant, 1 × 10 3 –3 × 10 3 , and the fraction of such centers is ca. 0.2 for cyclohexanone and tert -butanol and ca. 0.4 for cyclohexanol. The second type of centers possesses a relatively low affinity to guest molecules (the adsorption equilibrium constant varies from 1.8 to 9) and occupies the rest of the surface of the adsorbent The centers with a strong affinity to oxygen-containing guests are associated with chromium atoms within MIL framework.