Missing-linker Defects in Covalent Organic Framework Membranes for Efficient CO2 Separation
Zheyuan Guo1,2, Hong Wu1,2,3, Yu Chen2,4
1Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Angewandte Chemie (International Ed. in English)
|August 18, 2022
Summary
This study introduces defect engineering to create covalent organic framework (COF) membranes for efficient carbon dioxide (CO2) separation. The novel membranes exhibit high CO2 permeance and selectivity, offering a promising solution for gas separations.
Area of Science:
- Materials Science
- Chemical Engineering
- Nanotechnology
Background:
- Covalent organic framework (COF) membranes offer tunable channels and functional groups for molecular separations.
- The synergy of physical and chemical microenvironments in COFs is crucial for separation performance.
Purpose of the Study:
- To develop a defect engineering strategy for fabricating COF membranes.
- To enhance CO2 separation efficiency using COF membranes with abundant amino groups.
Main Methods:
- Fabrication of COF membranes using a defect engineering strategy.
- In situ generation of amino groups on COF nanosheets via missing-linker defects during monomer assembly.
- Assembly of COF nanosheets into membranes for gas separation testing.
Main Results:
- Generated abundant in situ amino groups on COF nanosheets, acting as CO2 facilitated transport carriers.
- Achieved high CO2 permeance (>300 GPU) and excellent selectivity for CO2/N2 (80) and CO2/CH4 (54) under humid conditions.
- Demonstrated the effectiveness of defect engineering for incorporating functional groups in COF membranes.
Conclusions:
- The defect engineering strategy provides a facile approach to creating functionalized COF membranes.
- The developed COF membranes show significant promise for efficient CO2 separation applications.
- This method can be extended to other organic framework membranes for diverse chemical separations.
