A charge-decorated porous framework with polar pores and open O donor sites for CO/CH and CH/CH separations.

Developing efficient adsorbent materials towards energy gas purification, CO 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 CO over CH. Moreover, the rich open O donor sites on the channel surface enable the resultant coordination polymer to selectively adsorb CH over CH 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.