Optimized Pore Nanospace through the Construction of a Cagelike Metal-Organic Framework for CO 2 /N 2 Separation.

The development of metal-organic framework (MOF) adsorbents with a potential molecule sieving effect for CO 2 capture and separation from flue gas is of critical importance for reducing the CO 2 emissions to the atmosphere yet challenging. Herein, a cagelike MOF with a suitable cage window size falling between CO 2 and N 2 and the cavity has been constructed to evaluate its CO 2 /N 2 separation performance. It is noteworthy that the introduction of coordinated dimethylamine (DMA) and N , N '-dimethylformamide (DMF) molecules not only significantly reduces the cage window size but also enhances the framework-CO 2 interaction via C-H···O hydrogen bonds, as proven by molecular modeling, thus leading to an improved CO 2 separation performance. Moreover, transient breakthrough experiments corroborate the efficient CO 2 /N 2 separation, revealing that the introduction of DMA and DMF molecules plays a vital role in the separation of a CO 2 /N 2 gas mixture.