A cage-based metal-organic framework with a unique tetrahedral node for size-selective CO2 capture

Optimized Pore Nanospace through the Construction of a Cagelike Metal–Organic Framework for CO2/N2 Separation

“…Recently, nonthermal-driven adsorption and separation technology based on porous solid materials has presented great potential in the CCS field due to its cost and energy efficiency, high capture capacity, and high selectivity. − In this respect, metal–organic frameworks (MOFs) have shown tremendous potential for CCS as a result of their structural diversity, function tunability, and high surface area. − Up to now, a great deal of effort has been devoted to improving the CO 2 uptake capacity and separation performance from flue gas via various crystal engineering strategies, in which pore-nanospace engineering represents an effective protocol for CCS achieved by tuning the pore size, volume, shape, and surface. − Generally, a MOF with a small pore size usually shows a high CO 2 selective adsorption performance but adversely leads to a low capture capacity, whereas a high pore volume can bestow the MOF with high uptake capacity but might reduce the adsorptive selectivity. , Therefore, engineering a MOF nanospace with the characteristics of small pore size and large pore volume might be an effective approach for achieving the trade-off between the adsorptive selectivity and uptake capacity, which can be accomplished through the construction of a cagelike MOF featuring a small window size and a large cavity. − Additionally, the window shape and internal cavity environment also play an important role in the selective adsorption process. In this regard, Feng, Zhou, and other groups have made pioneering contributions, demonstrating that pore-nanospace engineering via the construction of a cagelike MOF with suitable pore size/volume/shape/surface is an effective method to enhance the selective adsorption performance. − However, the elaborate design of a cage-based MOF with the appropriate pore volume/surface and precise window size falling between CO 2 and N 2 remains highly challenging.…”

Recent Advances of Multidentate Ligand-Based Anion-Pillared MOFs for Enhanced Separation and Purification Processes

“…It appears that the ith-d topology has become the only reported example of tridentate ligand-based APMOFs. In 2022, Zhang et al . reported a novel 3D cage-based copper-organic framework [Cu 4 (μ 4 -SO 4 )­(tpt) 4 ]·[SO 4 ], which was synthesized through the assemble of rare [Cu 4 (μ 4 -SO 4 )] tetrahedral units (four Cu­(I) ions are ligated by four O atoms from a SO 4 2– anion group) and tridentate N-containing ligands, 2,4,6-tri­(4-pyridinyl)-1,3,5-triazine (tpt), under solvothermal reaction conditions (Figures a and d).…”

Porous MOF Featuring 2D Intersecting Channels Based on a Pentanuclear Mn5(COO)10CO3 Cluster with Upgrading of Pipeline Natural Gas

“…Obviously, the maximum gas adsorption capacities under 100 kPa follow the sequence, CO 2 > C 2 H 6 > C 3 H 8 , which should be because C 3 H 8 with the largest kinetic diameter (4.3−5.118 Å) accumulates less in the limited pore volume of 1a compared smaller C 2 H 6 (4.443 Å) and CO 2 (3.3 Å) molecules. Although the adsorption amount of CO 2 at 298 K and 1 atm is lower than some MOFs, such as ZJNU-19 (106.5 cm 3 g −1 ), 42 Ni 2 (L) 2 (HCOO) 2 •4H 2 O (71.6 cm 3 g −1 ), 43 and ZJNU-88 (99.2 cm 3 g −1 ), 44 it is still more than some MOFs, such as UPC-71 (8.7 cm 3 g −1 ), 45 [Cu 4 (μ 4 -SO 4 )(tpt) 4 ]• [SO 4 ] (20.84 cm 3 g −1 ), 46 and UPC-72 (17.7 cm 3 g −1 ). 45 Furthermore, cyclic gas sorption isotherms for CO 2 at 298 K have been measured (Figure S10).…”