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

Abstract

Adsorption‐based separation is an important technology for C2H2 purification due to the environmentally friendly and energy‐efficient advantage. In addition to the high selectivity of C2H2/CO2, the high uptake of C2H2 also plays an important role in the separation progress. However, the trade‐off between adsorption capacity and separation performance is still in a dilemma. Herein, we report a series of cage‐like porous materials named FJI‐H8‐R (R=Me, Et, nPr and iPr) which all have high C2H2 uptakes at 1 bar and 298 K. Dynamic breakthrough studies show that they all exhibit excellent C2H2/CO2 separation performance. Particularly, FJI‐H8‐Me possesses a long breakthrough time up to 90 min g−1. Additionally, Grand Canonical Monte Carlo (GCMC) simulation reveals that the suitable pore space and geometry contribute much to the excellent separation performance.

Breaking the trade-off between selectivity and adsorption capacity for gas separation

“…S AC (1:1/2:1) values at 1 bar were thereby determined to be 10.0/9.4 ( SIFSIX-21-Cu ) > 9.5/9.0 ( NbOFFIVE-3-Cu ) > 8.3/8.1 ( TIFSIX-4-Cu ) > 7.8/7.8 ( SIFSIX-21-Ni ) > 7.6/7.4 ( TIFSIX-4-Ni ) > 6.0/5.9 ( NbOFFIVE-3-Ni ) ( Figures S45–S50 ). As presented in Table S1 , under relevant partial pressures, S AC for the six HUMs studied in this contribution were found to be comparable to leading C 2 H 2 -capture sorbents such as SIFSIX-Cu-TPA (5.3), 29 MUF-17 (6), 50 ZJU-60a (6.7), 51 FJU-22a (7.1), 33 TCuBr (9.5), 30 ZJUT-2a (10), 52 TIFSIX-2-Cu-i (10), 53 FJI-H8-Me (10.4), 28 and MIL-100(Fe) (12.5). 54 …”

“… 21 Nevertheless, there are >100,000 MOMs in the CSD MOF subset (2020.3 CSD release). 26 To the best of our knowledge, only a few (20) have been experimentally studied for C 2 H 2 /CO 2 separation under dynamic conditions (e.g., dynamic column breakthrough [DCB] experiments, see Table S1 ) including recently reported benchmarks set by ATC-Cu , 27 FJI-H8-Me , 28 and SIFSIX-Cu-TPA . 29 For example, ATC-Cu was found to exhibit an ideal adsorbed solution theory (IAST) selectivity of 53.6 for 1:1 C 2 H 2 /CO 2 separation.…”

Fluorinated metal–organic frameworks for gas separation

“…Compared to the FJI-H8-Me MOF with high thermal stability (around 320 1C) and high C 2 H 2 uptake (10.2 mmol g À1 ), the C 2 H 2 /CO 2 selectivity of about 10.2 is not comparable with that of UTSA-300a. 283 In another challenging separation, C 3 H 4 /C 3 H 6 (1/99 mixture), although UTSA-200a has a benchmark selectivity (20 000), 268 this F-MOF has low kinetic water stability and, therefore, is only recommended for the separation of pre-dried gases under low humidity conditions (Fig. 41).…”

A Microporous Potassium‐Organic Framework for Efficient C2H2/CO2 Separation

“…[18] In addition, a series of cage-like porous materials named FJIÀ H8-R (R = Me, Et, n Pr and i Pr) were synthesized by organic ligand group regulation, which all have high C 2 H 2 uptakes and FJIÀ H8-Me exhibits an excellent C 2 H 2 /CO 2 separation performance (breakthrough time up to 90 min/g at 298 K and 1 bar). [19] Many MOFs materials are composed of transition metals and organic ligands due to their strong metal coordination ability, such as Cr, Mn, Fe, Co, Cu, Zn, etc. [20][21][22][23][24] In contrast, MOFs construct by the first and second main group metals are less reported.…”

“…It possesses a unique pillar‐cage structure constructed by icosahedral and tetrahedral cages that exhibits high BET surface area, high C 2 H 2 uptake as well as excellent C 2 H 2 /CO 2 separation performance [18] . In addition, a series of cage‐like porous materials named FJI−H8‐R (R=Me, Et, n Pr and i Pr) were synthesized by organic ligand group regulation, which all have high C 2 H 2 uptakes and FJI−H8‐Me exhibits an excellent C 2 H 2 /CO 2 separation performance (breakthrough time up to 90 min/g at 298 K and 1 bar) [19] …”