Synthesis optimization of the ultra-microporous [Ni₃(HCOO)₆] framework to improve its CH₄/N₂separation selectivity

Abstract

The adsorptive separation selectivities of CH4/N2were successfully improved from 4.0–4.8 to 7.0–7.5viasynthesis optimization of ultra-microporous [Ni3(HCOO)6] frameworks.

DFT-based evaluation of porous metal formates for the storage and separation of small molecules

“…For methane, no experimental isotherms that approach saturation have been reported; however, it is worth noting that maximal uptakes obtained from the extrapolation of low-pressure isotherms in Co(fa) 2 and Ni(fa) 2 range between 1.36 and 2.20 mmol g -1 . [20,21] When the higher weight of the metal centres is taken into account, the highest of these values corresponds almost exactly to the equivalent of four molecules/cell (one per segment).…”

“…In this context, it is regrettable that the lack of lattice parameters determined for the fully desolvated system prevented an inclusion of Ni(fa) 2 in this study, as this system has been studied experimentally for the separation of CH 4 /N 2 mixtures. [20,21] As a final point regarding the selective adsorption of methane, it is worth noting that the difference in affinity observed in Mg(fa) 2 is virtually as high as for Zn(fa) 2 for CH 4 /N 2 mixtures, and only one kJ mol -1 smaller for CH 4 /H 2 mixtures. Due to its lower weight, resulting in higher possible uptakes, magnesium formate might thus be an attractive alternative to the previously investigated nickel-and cobalt-containing systems.…”

“…In the field of gas separation, recent efforts have addressed the separation of Xe/Kr mixtures using Co(fa) 2 and Ni(fa) 2 , [19] and the selective adsorption of methane over N 2 in the same two systems. [20,21] Relatively high M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 selectivities were observed for these challenging separations. A very recent experimental study has revealed promising selectivities towards CO 2 /N 2 and CH 4 /N 2 mixtures, and a moderate selectivity towards a CO 2 /CH 4 mixture, in a magnesium formate system that has an expanded unit cell when compared to α-Mg(fa) 2 .…”

Ultrafast water sensing and thermal imaging by a metal-organic framework with switchable luminescence

“…The as-prepared hydrated LIFM-CL1-H 2 O [Zn(hpi2cf)(DMF)(H 2 O), DMF= N , N -dimethylformamide, H 2 hpi2cf=5-(2-(5-fluoro-2-hydroxyphenyl)-4,5-bis(4-fluorophenyl)-1 H -imidazol-1-yl)isophthalic acid] features amphipathic microporosity (<3 Å) with surprisingly facile and reversible removal/uptake of coordinating water molecules under mild conditions (dry gas blowing or gentle heating)404142, giving rise to the dehydrated form LIFM-CL1 [Zn(hpi2cf)(DMF)] via a single-crystal-to-single-crystal (SC–SC) transformation (LIFM-CL1-H 2 O↔LIFM-CL1+H 2 O) and simultaneously ESIPT-related two-colour luminescence switching4344. This swift water-driven structural transformation and PL-switching property makes the present Zn-MOF one of the most powerful water sensors known so far owing to its hypersensitive response towards water molecules on a molecular level45, showing the following characteristics: the fastest PL responsiveness on the order of seconds, solely water interaction, easy stimulation and nondestructive regeneration, convenient material utilization from either hydrated or dehydrated forms, and multiply detection ways including emission wavelength, intensity or Commission Internationale de L'Eclairage (CIE) coordinate.…”

[Ni3(HCOO)6]/Poly(styrene‐b‐butadiene‐b‐styrene) Mixed‐Matrix Membranes for CH4/N2 Gas Separation

“…Increasing the UiO-66-NH 2 loading to 40 wt % led to 46 barrer CO 2 permeability, which is an eightfold increase over unfilled polysulfone, whereas the selectivity of CO 2 /CH 4 and CO 2 /N 2 stayed largely the same. Perez 6 ] can reach 2.102 mmol g -1 at 298 K for pure gas adsorption [33]. On the other hand, [Ni 3 (HCOO) 6 ] showed outstanding CH 4 separation performance over N 2 , verifying that CH 4 has a stronger affinity with [Ni 3 (HCOO) 6 ] compared with N 2 .…”