Additive-Induced Supramolecular Isomerism and Enhancement of Robustness in Co(II)-Based MOFs for Efficiently Trapping Acetylene from Acetylene-Containing Mixtures

Abstract

Although supramolecular isomerism in metal-organic frameworks (MOFs) would offer a favorable platform for in-depth exploring their structure-property relationship, the design and synthesis of the isomers are still rather a challenging aspect of crystal engineering. Here, a pair of supramolecular isomers of Co(II)-based MOFs (FJU-88 and FJU-89) can be directionally fabricated by rational tuning the additives. In spite of the fact that the isomers have the similar Co secondary building units and organic linkers, they adopt distinct networks with acs and snw topologies, respectively, which derive from the conformational flexibility of the organic ligands. It is noteworthy that the porous structure of FJU-88 would be collapsed after removal of the solvent from the pores. But FJU-89a shows permanent porosity accompanied with unusual hierarchical micro- and mesopores and superior gas selective adsorption performance. In addition, FJU-89a can efficiently trap CH from CH/CO and CH/CH mixture gases through fixed-bed dynamic breakthrough experiments.

Cage‐Like Porous Materials with Simultaneous High C2H2Storage and Excellent C2H2/CO2Separation Performance

“…The breakthrough data depicted in Figure 5 a clearly demonstrate that the CO 2 gas passed through the adsorption bed at first, while C 2 H 2 was retained in the packed column with the retention time of 90 min g −1 . The C 2 H 2 /CO 2 separation performance of FJI‐H8‐Me surpasses the famous SNNU‐45 (79 min g −1 ), [12] JNU‐1 (34.1 min g −1 ), [24] ZJNU‐13 (58 min g −1 ) [25] and FJU‐89a (33.3 min g −1 ) [26] under the same conditions and comparable to ATC‐Cu [27] . Additionally, FJI‐H8‐Me shows good reusability in the breakthrough experiments.…”

Cage‐Like Porous Materials with Simultaneous High C2H2Storage and Excellent C2H2/CO2Separation Performance

“…The breakthrough data depicted in Figure 5 a clearly demonstrate that the CO 2 gas passed through the adsorption bed at first, while C 2 H 2 was retained in the packed column with the retention time of 90 min g −1 . The C 2 H 2 /CO 2 separation performance of FJI‐H8‐Me surpasses the famous SNNU‐45 (79 min g −1 ), [12] JNU‐1 (34.1 min g −1 ), [24] ZJNU‐13 (58 min g −1 ) [25] and FJU‐89a (33.3 min g −1 ) [26] under the same conditions and comparable to ATC‐Cu [27] . Additionally, FJI‐H8‐Me shows good reusability in the breakthrough experiments.…”

Ultramicroporous Building Units as a Path to Bi‐microporous Metal–Organic Frameworks with High Acetylene Storage and Separation Performance

“…As predicated, the C 2 H 2 adsorbed amounts increases with the decreasing temperature due to exothermic physical adsorption, reaching 201.0 cm 3 g −1 at 263 K, 193.0 cm 3 g −1 at 273 K, 151.4 cm 3 g −1 at 283 K, and 108.0 cm 3 g −1 at 308 K. It is noted that the uptake capacity at 273 K is remarkably high, which is only lower than several top MOFs at 273 K such as NJU‐Bai17 (295 cm 3 g −1 ) and ZJU‐5 (290 cm 3 g −1 ), but higher than those of most renowned MOFs, such as MOF‐505 (177 cm 3 g −1 ), and UTSA‐50 (114 cm 3 g −1 ) . At 298 K and 1 atm, the C 2 H 2 absorbed amounts of SNNU‐45 can be up to 134 cm 3 g −1 , which surpasses many famous MOFs with excellent separation performance, such as FJU‐89a (101 cm 3 g −1 ), JCM‐1 (75 cm 3 g −1 ), UTSA‐300a (69 cm 3 g −1 ), and NKMOF‐1‐Ni (61 cm 3 g −1 ) . Clearly, SNNU‐45 should be a good candidate for C 2 H 2 storage application.…”