Polyacrylonitrile-Derived Sponge-Like Micro/Macroporous Carbon for Selective CO₂ Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Efficient carbon dioxide (CO2) capture necessitates adsorbents with both macropores for diffusion and micropores for adsorption.
• Creating interconnected micro-/macroporous carbon structures with nitrogen species presents a significant synthetic challenge.

Purpose of the Study:

• To develop a novel sponge-like carbon material with a well-defined micro-/macroporous structure and enriched nitrogen species.
• To evaluate the material's performance for CO2 capture, particularly under dynamic flow conditions and low partial pressures.

Main Methods:

• Aqueous phase polymerization of acrylonitrile in the presence of graphene oxide.
• Pyrolysis of the resulting polymer composite to form the sponge-like carbon structure.
• Characterization of porous structure, nitrogen content, and CO2 adsorption performance.

Main Results:

• Successfully synthesized a sponge-like carbon with interconnected micro-/macropores and abundant nitrogen species.
• Achieved high CO2 dynamic selectivity over N2 (454) and CH4 (11).
• Demonstrated good CO2 capacity at 298 K under low CO2 partial pressure (0.17 bar).

Conclusions:

• The synergistic effect of the micro-/macroporous framework and nitrogen-rich sites enhances mass transfer and CO2 affinity.
• The developed porous carbon is a promising candidate for CO2 capture from flue gas and other applications.
• The synthesis method offers a viable route to advanced porous carbon materials for gas separation.