Dense Packing of Acetylene in a Stable and Low‐Cost Metal–Organic Framework for Efficient C₂H₂/CO₂Separation

Abstract

Porous materials for C 2 H 2 /CO 2 separation mostly suffer from high regeneration energy,p oor stability,o rh igh cost that largely dampen their industrial implementation. A desired adsorbent should have an optimal balance between excellent separation performance,h igh stability,a nd lowc ost. We herein report as table,l ow-cost, and easily scaled-up aluminum MOF (CAU-10-H) for highly efficient C 2 H 2 /CO 2 separation. The suitable pore confinement in CAU-10-H can not only provide multipoint binding interactions with C 2 H 2 but also enable the dense packing of C 2 H 2 inside the pores.T his material exhibits one of the highest C 2 H 2 storage densities of 392 gL À1 and highly selective adsorption of C 2 H 2 over CO 2 at ambient conditions,a chieved by al ow C 2 H 2 adsorption enthalpy( 27 kJ mol À1 ). Breakthrough experiments confirm its exceptional separation performance for C 2 H 2 /CO 2 mixtures, affording both large C 2 H 2 uptake of 3.3 mmol g À1 and high separation factor of 3.4. CAU-10-H achieves the benchmark balance between separation performance,stability,and cost for C 2 H 2 /CO 2 separation.

Optimizing Acetylene Sorption through Induced‐fit Transformations in a Chemically Stable Microporous Framework

“…This means that, assisted by the pores of FJI‐H36 , the packing efficiency of gaseous C 2 H 2 is significantly higher than that of liquid C 2 H 2 under the same conditions. To the best of our knowledge, the storage density of C 2 H 2 for FJI‐H36 can compare with the best MOF (MOF‐OH) (Table S3), [5c] higher than the almost reported top‐performing MOFs, such as CAU‐10H‐NH 2 (460 g L −1 ), [5b] ZNU‐1 (443 g L −1 ), [12a] CAU‐10‐H (392 g L −1 ), [9b] SIFSIX‐1‐Cu (387 g L −1 ), [5h] NOTT‐300 (381 g L −1 ), [8e] FeNi‐M′MOF(372 g L −1 ), [5d] UTSA‐74 (343 g L −1 ), [5g] JCM‐1 (334 g L −1 ), [17f] FJI‐H8 (317 g L −1 ), [14c] FJU‐90 (256 g L −1 ) [5e] …”

“…As shown in Figure 5a, the CO 2 firstly elutes from the fixed‐bed at 49.8 min g −1 , while the breakthrough of C 2 H 2 does not occur until at 85.5 min g −1 , corresponding to a breakthrough time of 35.7 min g −1 . The adsorption capacity of C 2 H 2 for FJI‐H36 under dynamic breakthrough is calculated to be 3.82 mmol g −1 , superior to those of many top‐performing MOFs, such as CAU‐10‐H (3.3 mmol g −1 ), [9b] FeNi‐M'MOF (2.98 mmol g −1 ), [5d] CuI@UiO‐66‐(COOH) 2 (2.89 mmol g −1 ), [9a] JNU‐1 (2.68 mmol g −1 ) [15a] . Moreover, the adsorption capacity of FJI‐H36 was kept unchanged in both adsorption and breakthrough cycles (Figure S13), implying its good recyclability for C 2 H 2 storage and purification.…”

Molecular Mechanisms behind Acetylene Adsorption and Selectivity in Functional Porous Materials

“…CAU‐10‐H, which can be produced in kilogram‐scale from simple isophthalic acid linkers and Al 2 (SO 4 ) 3 ⋅18 H 2 O through green synthetic procedures, was reported possessing suitable pore confinement to enable the dense packing of four C 2 H 2 molecules per unit cell and resulted in high C 2 H 2 /CO 2 selectivity (Figure 6). [69] Another Al‐based MOF, MIL‐160(Al), which can be made from an Al‐based salt and a biomass‐derived ligand in water, is considered one of the most promising candidates for practical C 2 H 2 /CO 2 separation [70, 71] . Another important step towards practical applications of MOFs for gas separation is shaping MOF powders into formed bodies, and it is encouraging to see a recent example where polyamide supported ZIF‐8 membrane demonstrated successful separation of mixtures of C 2 H 2 /CO 2 and C 2 H 2 /CH 4 [72] .…”

Spatial disposition of square-planar mononuclear nodes in metal–organic frameworks for C2H2/CO2separation

“…S1 †). [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] For example, a highly uorinated MOF material SIFSIX-Cu-TPA exhibits a very large C 2 H 2 adsorption of 185 cm 3 g −1 at 298 K and 1 bar with a moderate C 2 H 2 /CO 2 selectivity of 5.4. 31 This approach, however, may not necessarily favor C 2 H 2 adsorption as the overall mismatch of electrostatic potentials between the framework surface and C 2 H 2 molecule could disrupt and even reverse the selectivity.…”