A charge-decorated porous framework with polar pores and open O donor sites for CO2/CH4 and C2H2/C2H4 separations

Developing efficient adsorbent materials towards energy gas purification, e.g. CO2 removal from natural gas or hydrocarbon separation, is an important but extremely challenging task. Herein, taking advantage of a cationic bipyridinium ligand in competition with a multicarboxylate ligand for binding with metal ions, a porous material with open carboxylate oxygen atoms exposed on the pore surface has been demonstrated as an efficient adsorbent for gas separation. The polar environment arising from the cationic pyridinium moiety and the negative carboxylate group endows the title compound with selective affinity to CO2 over CH4. Moreover, the rich open O donor sites on the channel surface enable the resultant coordination polymer to selectively adsorb C2H2 over C2H4 through H-bonding interactions. The separation mechanism has been revealed by theoretical studies. This work provides a specific guidance for the design of applicable porous materials toward energy resource purification.

Automated summary

This study develops an efficient gas separation adsorbent based on porous materials, which can effectively remove carbon dioxide from natural gas and separate hydrocarbons. The material shows selective adsorption to CO2 and C2H2 through the use of specific ligands and cationic groups. The separation mechanism is revealed, providing specific guidance for the design of porous materials for energy resource purification.