Zr-MOFs for CF₄/CH₄, CH₄/H₂, and CH₄/N₂ separation: towards the goal of discovering stable and effective adsorbents

Abstract

The best Zr-MOF adsorbents among more than 100 Zr-MOFs are computationally identified for CF4/CH4, CH4/H2, and CH4/N2 separations using a multi-criteria approach.

Tuning the Pore Environment of MOFs toward Efficient CH4/N2 Separation under Humid Conditions

“…Metal–organic frameworks (MOFs) are constructed by bridging metal ions or clusters (nodes) and organic coordinating ligands. The emerging MOFs have recently attracted extensive attention for gas separation/purification because of their fascinating tunability for pore size, shape, and surface functionality. − To date, many MOFs, Ni-MA–BPY, Al-CDC, Co 3 (C 4 O 4 ) 2 (OH) 2 , SBMOF-1, ATC-Cu, Cu­(INA) 2 , Ni 3 (HCOO) 6 , Ni-MOF-74, and so forth, have been reported for CH 4 /N 2 separation. It is noteworthy that water vapor is inevitably present in natural gas in the actual separation process of CH 4 /N 2 . , Water vapor can lead to a pronounced decrease in the hydrothermal stability of MOFs because of the more robust metal–water bond relative to the metal–ligand. , Even when the hydrothermal stability is acceptable, most MOFs commonly show relatively high-water absorption affinity in humid environments, inducing competitive adsorption between gas and water and reducing their separation performances .…”

“…The emerging MOFs have recently attracted extensive attention for gas separation/purification because of their fascinating tunability for pore size, shape, and surface functionality. 7−21 To date, many MOFs, Ni-MA− BPY, 22 Al-CDC, 23 Co 3 (C 4 O 4 ) 2 (OH) 2 , 24 SBMOF-1, 25 ATC-Cu, 26 Cu(INA) 2 , 27 Ni 3 (HCOO) 6 , 28 Ni-MOF-74, 29 and so forth, 30 have been reported for CH 4 /N 2 separation. It is noteworthy that water vapor is inevitably present in natural gas in the actual separation process of CH 4 /N 2 .…”

Computational investigation of multifunctional MOFs for adsorption and membrane-based separation of CF4/CH4, CH4/H2, CH4/N2, and N2/H2 mixtures

“…15 As these two sorbates have similar properties, finding sorbents that can achieve efficient CF 4 /CH 4 separation is crucial. While a large variety of gas compositions has been studied earlier for CF 4 /CH 4 separation, 43 we preferred an equimolar mixture to be able to benchmark the results of this work with our earlier work 15 which was possibly the largest MOF screening work in terms of CF 4 /CH 4 separation. H 2 or N 2 removal from CH 4 is highly important in the context of natural gas separation for which equimolar binary mixtures are typically used.…”

“…24,31,43,44 For instance, CF 4 removal from CH 4 constitutes a significant stage of reducing greenhouse gas concentration in the air. 15 As these two sorbates have similar properties, finding sorbents that can achieve efficient CF 4 /CH 4 separation is crucial. While a large variety of gas compositions has been studied earlier for CF 4 /CH 4 separation, 43 we preferred an equimolar mixture to be able to benchmark the results of this work with our earlier work 15 which was possibly the largest MOF screening work in terms of CF 4 /CH 4 separation.…”

Structural and bonding properties of small hydrocarbons inside Ca(squarate)-metal organic framework: ab-initio study

“…These crystalline organic compounds are well-known for their exceptionally large pores and abilities to absorb and bind a wide range of molecules and ions. The ability to tune the organic linkers and/or metallic ion centers in MOFs results in a large collection of materials with unique properties [9][10][11][12]. MOFs, with appropriate organic/ linker topologies, are widely used for molecular and ionic adsorption/separation applications [13][14][15][16].…”