Print Email Facebook Twitter Confined Water Cluster Formation in Water Harvesting by Metal–Organic Frameworks Title Confined Water Cluster Formation in Water Harvesting by Metal–Organic Frameworks: CAU-10-H versus CAU-10-CH3 Author van der Veen, M.A. (TU Delft ChemE/Catalysis Engineering) Canossa, S. (TU Delft ChemE/Catalysis Engineering) Wahiduzzaman, Mohammad (University of Montpellier) Nenert, Gwilherm (Malvern Panalytical B. V., Almelo) Frohlich, Dominik (Fraunhofer Institute for Solar Energy Systems ISE,) Rega, D. (TU Delft ChemE/Catalysis Engineering) Reinsch, Helge (Christian-Albrechts-Universität zu Kiel) Shupletsov, Leonid (External organisation) Markey, Karen (Katholieke Universiteit Leuven) Date 2023 Abstract Several metal–organic frameworks (MOFs) excel in harvesting water from the air or as heat pumps as they show a steep increase in water uptake at 10–30 % relative humidity (RH%). A precise understanding of which structural characteristics govern such behavior is lacking. Herein, CAU-10-H and CAU-10-CH3 are studied with -H, -CH3 corresponding to the functions grafted to the organic linker. CAU-10-H shows a steep water uptake ≈18 RH% of interest for water harvesting, yet the subtle replacement of -H by -CH3 in the organic linker drastically changes the water adsorption behavior to less steep water uptake at much higher humidity values. The materials’ structural deformation and water ordering during adsorption with in situ sum-frequency generation, in situ X-ray diffraction, and molecular simulations are unraveled. In CAU-10-H, an energetically favorable water cluster is formed in the hydrophobic pore, tethered via H-bonds to the framework μ-OH groups, while for CAU-10-CH3, such a favorable cluster cannot form. By relating the findings to the features of water adsorption isotherms of a series of MOFs, it is concluded that favorable water adsorption occurs when sites of intermediate hydrophilicity are present in a hydrophobic structure, and the formation of energetically favorable water clusters is possible. Subject metal–organic frameworkssum-frequency generationwater clusterswater harvesting To reference this document use: http://resolver.tudelft.nl/uuid:254082dd-a7d7-4841-a896-ca33650e5418 DOI https://doi.org/10.1002/adma.202210050 ISSN 0935-9648 Source Advanced Materials Part of collection Institutional Repository Document type journal article Rights © 2023 M.A. van der Veen, S. Canossa, Mohammad Wahiduzzaman, Gwilherm Nenert, Dominik Frohlich, D. Rega, Helge Reinsch, Leonid Shupletsov, Karen Markey, More Authors Files PDF Advanced_Materials_2023_v ... eworks.pdf 3.37 MB Close viewer /islandora/object/uuid:254082dd-a7d7-4841-a896-ca33650e5418/datastream/OBJ/view