Xu Huiqin, Li Jia, Liu Lin, Liang Fu-Shun, Han Zheng-Bo
College of Chemistry, Liaoning University, Shenyang 110036, China.
Inorg Chem. 2023 Aug 21;62(33):13530-13536. doi: 10.1021/acs.inorgchem.3c01969. Epub 2023 Aug 9.
Metal-organic frameworks (MOFs) have attracted significant attention as sorbents for gas separation and purification. Ideally, an industrially potential adsorbent should combine exceptional gas uptake, excellent stability, and a lower regeneration energy; however, it remains a great challenge. Here, by utilizing the pore space partition (PSP) strategy, we develop three isostructural MOF materials (, , and ) based on pristine MIL-88(Co). The three pore-space-partitioned crystalline microporous MOFs have triangular bipyramid cages and segmented one-dimensional channels, and among them, exhibits the highest CO uptake capacity (4.35 mmol g) and good CO/N (29.7) and CO/CH (6.2) selectivity. The selectivity-capacity synergy endows it with excellent CO/N and CO/CH separation performance. Moreover, can complete desorption within 10 min. The satisfactory CO adsorption ability can be attributed to both microporous aperture arising from PSP and modification of the pore surface by the polar hydroxy group, which enhances the interaction between and CO molecules significantly. The exceptional regeneration property may be due to its lower CO isosteric heat of adsorption (23.6 kJ/mol). The developed pore-space-partitioned MIL-88(Co) material may have potential application to flue gas and natural gas purification.
金属有机框架材料（MOFs）作为气体分离和净化的吸附剂已引起了广泛关注。理想情况下，具有工业潜力的吸附剂应兼具出色的气体吸附量、优异的稳定性以及较低的再生能量；然而，这仍然是一个巨大的挑战。在此，通过采用孔隙空间划分（PSP）策略，我们基于原始的MIL-88(Co)开发了三种同构的MOF材料（、和）。这三种孔隙空间划分的结晶微孔MOF具有三角双锥笼和分段的一维通道，其中，表现出最高的CO吸附容量（4.35 mmol g）以及良好的CO/N（29.7）和CO/CH（6.2）选择性。选择性 - 容量协同作用赋予了它出色的CO/N和CO/CH分离性能。此外，能够在10分钟内完成解吸。令人满意的CO吸附能力可归因于PSP产生的微孔孔径以及极性羟基对孔表面的修饰，这显著增强了与CO分子之间的相互作用。其出色的再生性能可能归因于其较低的CO等量吸附热（23.6 kJ/mol）。所开发的孔隙空间划分的MIL-88(Co)材料可能在烟气和天然气净化方面具有潜在应用。
