Fluorido-bridged robust metal-organic frameworks for efficient C2H2/CO2 separation under moist conditions
Yi-Ming Gu1,2, You-You Yuan3, Cai-Lin Chen4
1Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China wangsd@dicp.ac.cn.
Chemical Science
|February 16, 2023
Summary
A novel fluorine-bridged iron metal-organic framework (Fe-MOF) efficiently captures acetylene from impurities. This material demonstrates superior acetylene adsorption and separation performance, even under humid conditions.
Area of Science:
- Materials Science
- Chemistry
- Chemical Engineering
Background:
- Acetylene production processes are often contaminated with carbon dioxide and moisture.
- Metal-organic frameworks (MOFs) with fluorine as hydrogen-bonding acceptors (HBAs) show promise for selective acetylene capture.
- Incorporating fluorine directly into metal clusters within MOFs remains a synthetic challenge.
Purpose of the Study:
- To synthesize and characterize a novel fluorine-bridged iron-based MOF (Fe-MOF) for acetylene capture.
- To investigate the acetylene adsorption and separation capabilities of the new Fe-MOF, particularly its interaction with CO2.
- To evaluate the stability and performance of the Fe-MOF under various humidity conditions.
Main Methods:
- Synthesis of a fluorine-bridged Fe-MOF (DNL-9(Fe)) using mixed-valence FeII/FeIII clusters and organic ligands.
- Characterization of the MOF structure and fluorine incorporation.
- Acetylene adsorption/desorption studies (static and dynamic), including acetylene/carbon dioxide separation tests.
- Computational modeling to understand adsorption mechanisms and enthalpy.
- Hydrochemical stability tests under aqueous, acidic, and basic conditions.
Main Results:
- A unique fluorine-bridged Fe-MOF, DNL-9(Fe), was successfully synthesized.
- The fluorine species in DNL-9(Fe) provide enhanced acetylene adsorption sites via hydrogen bonding, showing lower adsorption enthalpy compared to other HBAMOFs.
- DNL-9(Fe) exhibits excellent hydrochemical stability and maintains high acetylene/carbon dioxide separation performance even at 90% relative humidity.
Conclusions:
- The novel fluorine-bridged Fe-MOF, DNL-9(Fe), offers a promising platform for efficient acetylene capture and separation.
- Its unique fluorine incorporation strategy leads to superior acetylene affinity and stability, outperforming existing HBAMOFs.
- DNL-9(Fe) demonstrates significant potential for industrial applications in purifying acetylene, even in challenging humid environments.
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