While preferential adsorption of ethane (C2H6) over ethylene (C2H4) is more advantageous in industrial separation technology, most porous materials such as metal-organic frameworks, covalent-organic frameworks, and hydrogen-bonded organic frameworks provide C2H4-selective performance, and they suffer from poor stability and large-scale synthesis problems required for practical applications. Herein, we report the synthesis and C2 gas separation properties of seven robust hypercrosslinked polymers (HCPs; HCP_TPB, HCP_TMPB, HCP_BCMBP, HCP_p-DCX, HCP_m-DCX, HCP_o-DCX, and HCP_CMBA) prepared from inexpensive starting monomers through the facile Friedel-Crafts reaction. Notably, HCP_TPB exhibited the highest C2H6 capture capacity among C2H6-selective metal-free adsorbents. The preferential C2H6 adsorption is associated with enhanced C-H⋯π interactions in the intrinsically nonpolar environments created by aromatic rings. In addition, a linear relationship between ethane uptake and surface area in porous organic frameworks was established for the first time. Breakthrough experiments demonstrated the selective separation of C2H6 from C2H6/C2H4 mixtures and the recyclability of HCP_TPB and HCP_TMPB. This work provides a design basis for the development of scalable, robust C2H6-selective adsorbents by tuning the nonpolar pore environment.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)