Improving Ethane/Ethylene Separation Performance of Isoreticular Metal–Organic Frameworks via Substituent Engineering

Abstract

The preferential capture of ethane (C 2 H 6 ) over ethylene (C 2 H 4 ) presents a very cost-effective and energy-saving means applied to adsorptive separation and purification of C 2 H 4 with a high product purity, which is however challenged by low selectivity originating from their similar molecular sizes and physical properties. Substituent engineering has been widely employed for selectivity regulation and improvement, but its effect on C 2 H 6 /C 2 H 4 separation has been rarely explored to date. In this work, four isoreticular coordination framework compounds based on 5-(pyridin-3-yl)isophthalate ligands bearing different substituents were rationally constructed. As revealed by isotherm measurements, thermodynamic studies, and IAST computations, they exhibited promising utility for C 2 H 6 /C 2 H 4 separation with moderate adsorption heat and a high uptake amount at a relatively low-pressure domain. Furthermore, the C 2 H 6 /C 2 H 4 separation potential can be finely tuned and optimized via purposeful substituent alteration. Most remarkably, functionalization with a nonpolar methyl group yielded an improved separation efficiency compared to its parent compound. This work offers a good reference value for enhancing the C 2 H 6 /C 2 H 4 separation efficiency of MOFs by engineering the pore microenvironment and dimensions via substituent manipulation.

Boosting C2H6/C2H4 separation in scalable metal‐organic frameworks through pore engineering

“…The value of Q st for C 2 H 6 was found to be higher than that for C 2 H 4 , confirming that the frameworks have a stronger affinity for C 2 H 6 (Figures 3A and S11). Furthermore, compared with several top‐performing C 2 H 6 ‐selective MOFs, such as Fe 2 (O 2 )(dobdc) (66.8 kJ mol −1 ), 10 MAF‐49 (60.0 kJ mol −1 ), 24 IRMOF‐8 (52.5 kJ mol −1 ), 26 UIO‐NDC (58.0 kJ mol −1 ), 27 UIO‐66 (53.0 kJ mol −1 ), 27 NKMOF‐8‐Br (40.8 kJ mol −1 ), 28 ZJNU‐21(37.4 kJ mol −1 ), 29 Cr‐BTC(O 2 ) (37.2 kJ mol −1 ), 30 and JNU‐2 (30 kJ mol −1 ), 31 the relatively low Q st value (20.1 kJ mol −1 ) of Cu‐cam‐pyz is conducive to material regeneration (Figure 3A).…”

Recent advances in metal–organic frameworks for gas adsorption/separation

“…The result also revealed that methyl is a significant functional group to elevate the separation performance. 74 Similarly, with methylation, Noro et al observed the apparent confinement effect to limit the guest into the channel. 75 These are representative samples by functionalization to elevate the separation efficiency.…”

Incorporating Fullerenes in Nanoscale Metal–Organic Matrixes: An Ultrasensitive Platform for Impedimetric Aptasensing of Tobramycin

“…In terms of achieving functional materials with task-specific functionality, the development of composite materials has drawn attention via assembling various constituents at atomic and molecular levels. Metal–organic frameworks (MOFs) have well-developed porosity, ordered structures, and various morphologies, resulting in their extensive utilization in sorption, , sensor, − and heterogeneous catalysis. − Unfortunately, the poor electrochemical activity and stability of MOFs significantly limit their use in electrochemical analysis. Hence, various materials have been implemented to combine with MOFs for enhanced electrochemical activity, such as metal nanoparticles, graphene, , and carbon nanotubes .…”