Water Adsorption in Metal-Organic Frameworks: Characteristics, Mechanisms, and Structure-Property Relationships
Shiue-Min Shih1, Li-Chiang Lin1,2
1Department of Chemical Engineering, National Taiwan University, Taipei 106319, Taiwan.
Journal of the American Chemical Society
|September 10, 2025
Summary
Metal-organic frameworks (MOFs) offer a promising strategy for atmospheric water harvesting. This study reveals complex water adsorption behaviors in MOFs and identifies key design principles for efficient water capture materials.
Area of Science:
- Materials Science
- Chemistry
- Environmental Science
Background:
- Limited water availability necessitates innovative water harvesting solutions.
- Metal-organic frameworks (MOFs) show potential for capturing atmospheric water vapor.
- Understanding MOF adsorption characteristics is crucial for effective water harvesting.
Purpose of the Study:
- To systematically investigate water adsorption behaviors in a diverse set of over 200 MOFs.
- To elucidate the influence of MOF properties on water adsorption characteristics and harvesting effectiveness.
- To identify key design principles for developing advanced MOF-based atmospheric water harvesting adsorbents.
Main Methods:
- Computational screening of >200 MOFs for water adsorption properties.
- Analysis of water adsorption isotherms, including non-S-shaped and S-shaped types.
- Investigation of phase behaviors, macrostate probability distributions (MPDs), thermodynamic stability, and free energy landscapes.
- Structure-property relationship analysis to identify design principles.
Main Results:
- Discovered diverse and complex water adsorption behaviors in MOFs, including various subtypes of non-S-shaped and S-shaped isotherms.
- Identified distinct phase behaviors within S-shaped isotherms, linked to different adsorption mechanisms and hydrogen-bonding environments.
- Uncovered critical design principles: moderate heat of adsorption for S-shaped isotherms, pore size for adsorption step steepness, and adsorption site density/uniformity for step pressure.
Conclusions:
- Water adsorption in MOFs is highly complex, exhibiting diverse isotherm shapes and phase behaviors.
- Key MOF properties like heat of adsorption, pore size, and adsorption site characteristics critically influence water capture performance.
- This study provides a comprehensive understanding of MOF water adsorption and offers design guidelines for superior atmospheric water harvesting materials.
More Related Videos
08:12Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance
Published on: September 5, 2018
16.5K
06:45Author Spotlight: Characterizing Porous Materials for Aiding the Development of Robust Metal-Organic Frameworks with Adsorption Behavior
Published on: March 8, 2024
9.7K
Related Concept Videos
02:51Metal-Ligand Bonds
23.8K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
23.8K
01:23Properties of Organometallic Compounds
1.6K
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
1.6K
00:56Extraction: Advanced Methods
1.0K
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
1.0K
02:58Crystal Field Theory - Octahedral Complexes
30.4K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.4K
02:32Bonding in Metals
51.6K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
51.6K