Water Vapor Adsorption on CAU-10- X: Effect of Functional Groups on Adsorption Equilibrium and Mechanisms

Marina V Solovyeva; Alexandr I Shkatulov; Larisa G Gordeeva; Elizaveta A Fedorova; Tamara A Krieger; Yuri I Aristov

doi:10.1021/acs.langmuir.0c02729

Water Vapor Adsorption on CAU-10- X: Effect of Functional Groups on Adsorption Equilibrium and Mechanisms

Langmuir. 2021 Jan 19;37(2):693-702. doi: 10.1021/acs.langmuir.0c02729. Epub 2021 Jan 7.

Authors

Marina V Solovyeva^{1

2}, Alexandr I Shkatulov³, Larisa G Gordeeva^{1

2}, Elizaveta A Fedorova¹, Tamara A Krieger¹, Yuri I Aristov^{1

2}

Affiliations

¹ Boreskov Institute of Catalysis, Novosibirsk, Ac. Lavrentiev av. 5, Novosibirsk 630090, Russia.
² Novosibirsk State University, Novosibirsk, Pirogova str. 2, Novosibirsk 630090, Russia.
³ Eindhoven University of Technology, Department of Applied Physics, De Rondom 70, 5612 AP, Eindhoven, The Netherlands.

Abstract

Metal-organic frameworks (MOFs) possess unique flexibility of structure and properties, which drives them toward applications as water adsorbents in many emerging technologies, such as adsorptive heat transformation, water harvesting from the air, dehumidification, and desalination. A deep understanding of the surface phenomena is a prerequisite for the target-oriented design of MOFs with the required adsorption properties. In this work, we comprehensively study the effect of functional groups on water adsorption on a series CAU-10-X substituted with both hydrophilic (X = NH₂) and hydrophobic (X = NO₂) groups in the linker. The adsorption equilibrium is measured at P = 7.6-42 mbar and T = 5-100 °C. The study of water adsorption by a set of mutually complementary physicochemical methods (TG, XRD in situ, FTIR, and ¹H NMR relaxometry) elucidates the nature of primary adsorption sites and water adsorption mechanisms.