Microporous Metal-Containing Hydrogen-Bonded Organic Frameworks with Benchmark C₂H₂ Storage Density for Efficient...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient separation of acetylene (C2H2) from industrial gas mixtures like CO2 and C2H4 is crucial but challenging.
• Adsorptive techniques using porous materials offer energy-efficient solutions.
• Developing multifunctional porous materials with high selectivity and capacity is a key research area.

Purpose of the Study:

• To report the development of isostructural metal-containing hydrogen-bonded organic frameworks (M-HOFs) for gas separation.
• To evaluate the performance of M-HOFs in separating C2H2 from CO2 and C2H4 mixtures.
• To investigate the mechanism of C2H2 capture and selectivity in these novel materials.

Main Methods:

• Synthesis of isostructural M-HOFs featuring micropore channels with uncoordinated carboxyl groups.
• Single-crystal X-ray diffraction analysis to determine the crystal structure and interaction sites.
• Gas adsorption and breakthrough experiments to assess C2H2 capture capacity, selectivity, and separation efficiency.

Main Results:

• M-HOFs exhibit high C2H2 capture density (396.0 mg cm-3) via hydrogen bonding with carboxyl groups.
• Exceptional selectivity was observed for C2H2 over C2H4 (420-97) and CO2 (188-53).
• Efficient separation of binary gas mixtures was confirmed, with high C2H4 productivity (137.4 mol kg-1) and a separation factor of 17 for C2H2/CO2.

Conclusions:

• The designed M-HOFs demonstrate superior performance in separating C2H2 from industrially relevant gas mixtures.
• The high C2H2 capture capability and selectivity are attributed to the specific pore structure and functional groups.
• These M-HOFs show significant potential for practical, energy-efficient gas separation applications due to their stability and performance.