Crystal Engineering on Cu-Triazolate MOFs via Mixed-Linker Modulation for Selective Azeotropic Ethanol Dehydration

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for various applications.
• Copper-triazolate (Cu-Tz) MOFs are investigated for adsorption and separation processes.
• Controlling MOF morphology is crucial for optimizing performance.

Purpose of the Study:

• To develop a mixed-linker synthetic strategy for copper-triazolate metal-organic frameworks (Cu-Tz MOFs).
• To engineer MOF morphology by modulating hydrophilicity, pore cavity, and surface chemistry.
• To enhance water removal performance from azeotropic water-ethanol mixtures.

Main Methods:

• Employed a mixed-linker synthetic strategy using parent triazole with amino- and thioether-functionalized triazoles.
• Controlled crystal growth to engineer MOF morphology.
• Utilized thermal activation to create accessible Cu(II) open metal sites.

Main Results:

• Successfully synthesized mixed-linker Cu-Tz MOFs with modulated hydrophilicity, pore cavity, and surface chemistry.
• Achieved enhanced hydrophilicity and porosity in the mixed-linker MOFs after thermal activation.
• Demonstrated superior water removal performance from azeotropic water-ethanol mixtures compared to parent CuTz.

Conclusions:

• Mixed-linker strategy is effective for engineering Cu-Tz MOF morphology and properties.
• Enhanced hydrophilicity and porosity are key factors for improved water separation.
• These engineered MOFs show significant potential for efficient water-ethanol mixture separation.