Skip to main content
NCBI home page
ACS AuthorChoice logoLink to ACS AuthorChoice
. 2023 Dec 1;6(1):56–65. doi: 10.1021/acsmaterialslett.3c01157

Ultramicroporous Lonsdaleite Topology MOF with High Propane Uptake and Propane/Methane Selectivity for Propane Capture from Simulated Natural Gas

Chenghua Deng †, Li Zhao ‡, Mei-Yan Gao †, Shaza Darwish †, Bai-Qiao Song †, Debobroto Sensharma †, Matteo Lusi †, Yun-Lei Peng ‡,*, Soumya Mukherjee †,*, Michael J Zaworotko †,*
PMCID: PMC10762655  PMID: 38178981

Abstract

graphic file with name tz3c01157_0007.jpg

Propane (C3H8) is a widely used fuel gas. Metal–organic framework (MOF) physisorbents that are C3H8 selective offer the potential to significantly reduce the energy footprint for capturing C3H8 from natural gas, where C3H8 is typically present as a minor component. Here we report the C3H8 recovery performance of a previously unreported lonsdaleite, lon, topology MOF, a chiral metal–organic material, [Ni(S-IEDC)(bipy)(SCN)]n, CMOM-7. CMOM-7 was prepared from three low-cost precursors: Ni(SCN)2, S-indoline-2-carboxylic acid (S-IDECH), and 4,4′-bipyridine (bipy), and its structure was determined by single crystal X-ray crystallography. Pure gas adsorption isotherms revealed that CMOM-7 exhibited high C3H8 uptake (2.71 mmol g–1) at 0.05 bar, an indication of a higher affinity for C3H8 than both C2H6 and CH4. Dynamic column breakthrough experiments afforded high purity C3H8 capture from a gas mixture comprising C3H8/C2H6/CH4 (v/v/v = 5/10/85). Despite the dilute C3H8 stream, CMOM-7 registered a high dynamic uptake of C3H8 and a breakthrough time difference between C3H8 and C2H6 of 79.5 min g–1, superior to those of previous MOF physisorbents studied under the same flow rate. Analysis of crystallographic data and Grand Canonical Monte Carlo simulations provides insight into the two C3H8 binding sites in CMOM-7, both of which are driven by C–H···π and hydrogen bonding interactions.

Propane (C3H8) is a widely utilized hydrocarbon that is a gas under ambient conditions. As a combustible and highly flammable fuel gas,1−8 compression of C3H8 is key to its storage and delivery as liquified petroleum gas.1,2 Thanks to its thermodynamic properties, C3H8 is also recognized as an eco-friendly refrigerant.3,4 Further, C3H8 is involved in production of high-value chemicals, polypropylene, and polyethylene.5,6 In addition, in semiconductor manufacturing, C3H8 is a precursor gas for silicon carbide deposition.7,8

C3H8 is generally produced by either of two routes: 1) extraction from petroleum refining; 2) extraction from natural gas (NG). NG is a mixture of hydrocarbons, primarily composed of methane (CH4) and smaller amounts of ethane (C2H6), C3H8, and other gases.1,9−11 Low C3H8 concentration in NG pipelines is desirable as it mitigates condensation reactions.12Scheme 1 illustrates the preparation of C3H8 and its utility as a commodity chemical. The global C3H8 market reached 174.3 million tons in 2022, with a 2028 market forecast as high as 223.1 million tons.13 Despite this surging demand, energy-intensive distillation remains state-of-the-art to obtain C3H8 from petroleum refining products and NG.14,15 Overall, distillation processes account for 45–55% of the energy footprint of the chemical industry, a sector that consumes ca. 15% of global energy consumption.16 To mitigate this energy footprint, adsorptive separation using physisorbents is emerging as an alternative to distillation and extractions.16−18 Specifically, C3H8-selective physisorbents that capture C3H8 from NG are of interest as they will save energy, potentially leading to process optimization for NG purification.19−21

Scheme 1. Preparation and Application of Propane.

Scheme 1

Open in a new tab

Metal–organic materials (MOMs), also known as porous coordination polymers (PCPs) and metal–organic frameworks (MOFs), are porous materials typically comprised of coordination bond-linked metal cations or metal clusters and organic ligands that serve as linkers.22−25 Compared to traditional porous materials like zeolites, porous carbons and silica, MOMs are amenable to crystal engineering,26 enabling chemists to control pore size, shape and chemistry.18,19,26−30 In the context of NG purification, molar mass and polarizability gradually increase from CH4 to C2H6 to C3H8 (Table S3).31 The kinetic diameters of C2H6 (4.44 Å) and C3H8 (4.3 Å) are near-identical, both higher than that of CH4 (3.76 Å). A CH4/C2H6/C3H8 (85:10:5, v/v) ternary mixture is generally regarded as a suitable composition for studying the NG purification potential of a sorbent. This separation remains understudied with physisorbents tending to coadsorb C2H6 and C3H8, thereby affording high-purity CH4.32−38 To the best of our knowledge, only three studies have demonstrated separation of C3H8 from C2H6 by MOMs from a relevant CH4/C2H6/C3H8 (85:10:5) gas mixture.39−41 Developing an MOM with both high selectivity and high dynamic uptake for C3H8 is a challenge that we address herein.

We have previously reported that rod building blocks (RBBs) and low-cost abundant linker ligands, e.g., mandelic acid and S-indoline-2-carboxylic acid (S-IDECH), can afford families of chiral MOMs, CMOMs.42−46 These CMOMs are modular as they are composed of divalent metal cations, e.g., Co2+ or Zn2+, that form RBBs involving mandelate or related anions cross-linked by 4,4′-bipyridine (bipy) linkers. These structures can form cationic bnn or dia porous coordination networks with extra-framework counteranions. In this study, we introduce a new CMOM variant which contains a coordinated thiocyanate, and report its gas sorption properties and separation performance.

Experimental Section

Reagents (≥98% purity) and solvents were procured from commercial vendors and used without further purification, except for nickel(II) thiocyanate (Ni(SCN)2), which was prepared by the reaction of nickel(II) carbonate (NiCO3) and potassium thiocyanate (KSCN).47 Full details on synthesis procedures are given in the experimental section of the Supporting Information.

Synthesis and Solvent Exchange

A methanolic solution of Ni(SCN)2 was added to an N,N-dimethylformamide (DMF) solution of bipy, and S-IDECH (molar ratios of Ni(SCN)2: bipy: S-IDECH = 1:1:1) in a 15 mL glass vial. Blue crystals of {[Ni(S-IDEC)(bipy)(SCN)](DMF)1.5}n, CMOM-7-DMF, were obtained after the vial was heated in an oven at 85 °C for 24 h. After soaking crystals of CMOM-7-DMF in methanol for 5 days with fresh solvent exchange every day, the crystals transformed into {[Ni(S-IDEC)(bipy)(SCN)](MeOH)3}n, CMOM-7-MeOH. Crystals of CMOM-7-MeOH were used for subsequent gas sorption and dynamic column breakthrough experiments.

Pure Gas Sorption Isotherms

A sample of CMOM-7-MeOH was activated under high vacuum using a Micromeritics Smart VacPrep at 60 °C for 12 h before gas sorption experiments. The crystals were found to transform to [Ni(S-IDEC)(bipy)(SCN)]n, the activated form of CMOM-7. 77 K N2 and 195 K CO2 sorption isotherms were recorded by a Micromeritics TriStar II Plus surface area and porosity analyzer. CO2, CH4, acetylene (C2H2), ethylene (C2H4), C2H6, C3H8, propylene (C3H6) and C3H4 sorption isotherms were collected with a Micromeritics 3Flex adsorption analyzer.

Dynamic Column Breakthrough (DCB) Experiment

About 0.88 g of activated CMOM-7 was used as a packed fixed-bed in quartz tubing (Φ 6 × 400 mm, outer diameter = 8 mm) inside a dynamic column breakthrough instrument (Figures S22 and S23).48 The packed sample was purged under a 20 cm3 min–1 flow of helium at 80 °C for 1 h prior to conducting each breakthrough experiment. The composition of the outlet gas during the breakthrough experiments was monitored by a Shimadzu Nexis GC-2030 gas chromatograph (GC) with a flame ionization detector (FID) and a thermal conductivity detector (TCD).

We recently reported the structure of CMOM-5[NO3] ([Ni(S-IDEC)(bipy)(H2O)][NO3]) in which nickel cations are octahedrally coordinated to S-IDEC, bipy and an aqua ligand to afford a cationic RBB (Figure 1a,b) which, when connected by bipy linkers, afforded a cationic dia net.46CMOM-7 was prepared using Ni(SCN)2 rather than Ni(NO3)2. Single-crystal X-ray diffraction (SCXRD) studies revealed that the as-synthesized phase, {[Ni(S-IDEC)(bipy)(SCN)](DMF)1.5}n, CMOM-7-DMF, had crystallized in the monoclinic space group P212121 (Table S1), the same as that of CMOM-5[NO3]. The asymmetric unit of CMOM-7-DMF was found to contain three DMF molecules, a pair of Ni2+ cations coordinated to two thiocyanate anions, two S-IDEC anions, and two bipy ligands. The Ni2+ cations in CMOM-7 exhibit the same coordination environment as that in CMOM-5 but with the aqua ligand of CMOM-5 substituted by thiocyanate (Figure 1a,c). The ratio of Ni2+/S-IDEC/bipy in both CMOM-5 and CMOM-7 is 1:1:1 and, as the RBB in CMOM-7 is neutral,46,49 there are no extra-framework anions.

Figure 1.

Figure 1

Open in a new tab

Structural differences between CMOM-5 and CMOM-7. (a) Schematic illustration of the repeating units that form the RBBs of CMOM-5 (left) and CMOM-7 (right); N1 and N2 correspond to the bipy linkers opposite and perpendicular to the terminally coordinated ligands, respectively. (b) The cationic RBB of CMOM-5. (c) Neutral RBB of CMOM-7. (d) The crystal structure of CMOM-5, and the coordination geometry around bipy (left). (e) The crystal structure of CMOM-7, including the coordination geometries around bipy-1 (left) and bipy-2 (right). (f) Overlay plot of a bipy linker from CMOM-5 and bipy-1 of CMOM-7. (g) Overlay plot of a bipy linker from CMOM-5 and bipy-2 of CMOM-7. (h) The dia network topology of CMOM-5 and the [64] tile generated thereof. (i) The lon network topology of CMOM-7, alongside the frameworks of [65] and [63] tiles generated thereof. Solvent molecules were omitted for clarity.

In the S-IDEC RBBs, we define the coordination sites of bipy as N1 and N2, corresponding to the positions opposite the nitrogen atom from S-IDEC or opposite the terminal coordinated ligands (aqua ligand and SCN–), respectively (Figure 1a). The asymmetric unit of CMOM-5[NO3] is comprised of one bipy coordinated to two Ni2+ sites through N1 and N2 positions (Figure 1d). Conversely, the asymmetric unit of CMOM-7-DMF contains two bipy linkers, one linked to two nickel cations through the N1 sites, and another linked to two nickel cations through the N2 sites (Figure 1e); bipy-1 and bipy-2, respectively. Overlay plots of the frameworks of CMOM-5[NO3] and CMOM-7 around the bipy linkers reveals that the RBBs are linked differently (Figure 1f,g). Specifically, RBBs in CMOM-5 lie parallel to the crystallographic a axis (Figures 1d and S2), whereas in CMOM-7 RBBs extend along the crystallographic c axis with adjacent RBBs being antiparallel (Figures 1e and S2). The topologies of CMOM-5 and CMOM-7 are diamondoid, dia, and Lonsdaleite, lon, respectively. Both 4-c topologies have the same point ({66}) and vertex symbols ({62.62.62.62.62.62}). However, the dia net is based upon [64] tiles (Figure 1h), whereas the lon net comprises from [63] and [65] tiles (Figure 1i).50,51

CMOM-7-DMF was activated by soaking in methanol, transforming it to CMOM-7-MeOH, and exposure to vacuum. CMOM-7-MeOH and activated CMOM-7 retained space group P212121 (Tables S1 and S2) with unit cell parameters similar to CMOM-7-DMF. The unit cell volume of CMOM-7 (5286.10(19) Å3) was found to be slightly smaller than those of CMOM-7-DMF (5365.1(3) Å3) and CMOM-7-MeOH (5382.4(2) Å3). Powder X-ray diffraction (PXRD) diffractograms demonstrated phase purity and retention of crystallinity (Figure S5). Variable temperature PXRD (VT-PXRD) studies conducted upon CMOM-7-MeOH revealed the retention of crystallinity below 225 °C (Figure S8). Thermogravimetric analysis (TGA) conducted upon CMOM-7-DMF revealed a weight loss of ca. 18 wt % at ca. 180 °C (Figure S9), consistent with loss of DMF guest molecules, and thermal decomposition starting at ca. 255 °C. TGA data for CMOM-7-MeOH revealed a weight loss of 14.11 wt % at 73 °C, corresponding to the loss of methanol. CMOM-7 did not register any significant weight loss before thermal decomposition at ca. 255 °C.

To investigate porosity, 195 K CO2 and 77 K N2 gas sorption experiments were conducted on CMOM-7, both of which exhibited typical Type-I isotherms52 with saturation uptakes of 9.44 mmol g–1 (CO2, 195 K) and 9.48 mmol g–1 (N2, 77 K), respectively (Figures 2a and S11). High-pressure CO2 sorption also resulted in a Type-I isotherm, registering an uptake of 7.32 mmol g–1 at 298 K and 40 bar (Figure S12). Langmuir surface areas determined from the 195 K CO2 and 77 K N2 sorption isotherms were consistent, 971.04 m2 g–1 and 919.11 m2 g–1, respectively (Figure S14). The BET (Brunauer–Emmett–Teller) surface areas determined from 195 K CO2 and 77 K N2 data were 868.01 m2 g–1 and 861.38 m2 g–1, respectively (Figure S15). Based on Horvath–Kawazoe (H–K) pore size distribution analysis of the 195 K CO2 and 77 K N2 adsorption isotherms, the mean pore width of CMOM-7 is calculated to be 5.3 and 8.9 Å, respectively (Figures 2a and S11).

Figure 2.

Figure 2

Open in a new tab

Single-component gas sorption studies of CMOM-7. (a) 195 K CO2 sorption isotherm of CMOM-7 and the corresponding H–K pore size distribution profile (inset). (b) CH4, C2H6 and C3H8 adsorption isotherms of CMOM-7 at 298 K. (c) Isosteric enthalpies of adsorption (Qst) of CMOM-7 for CH4, C2H6 and C3H8. (d) IAST selectivity of CMOM-7 for three binary mixtures of compositions: C3H8/CH4 (v/v = 5:85), C3H8/C2H6 (v/v = 5:10) and C2H6/CH4 (v/v = 10:85). (e) Comparison of C3H8 adsorption capacity and C3H8/CH4 (v/v = 5:85) IAST selectivities for a few select reported sorbents at 298 K and 1 bar. (f) Comparison of C3H8 adsorption capacity and C3H8/C2H6 (v/v = 1:1) IAST selectivities for a few select reported sorbents at 298 K and 1 bar.

The single-component gas sorption isotherms of C1 gases (CH4 and CO2), C2 gases (C2H2, C2H4 and C2H6) and C3 gases (C3H8, C3H6 and C3H4) were recorded at three temperatures, 273, 298, and 313 K (Figures 2b, S16 and S17), all of which are Type-I isotherms.52 At 298 K and 1 bar, CMOM-7 exhibited 1 bar uptakes for CH4, C2H6 and C3H8 of 0.68 mmol g–1, 3.10 mmol g–1 and 3.40 mmol g–1, respectively. At 298 K and 0.05 bar, the uptake of C3H8, 2.71 mmol g–1, was higher than that of C2H6 (0.61 mmol g–1) and much higher than that of CH4 (0.04 mmol g–1). The half-loading (0.05 bar) C3H8 uptake is comparable to leading NG separation sorbents such as MIL-160 (2.48 mmol g–1),36MOF-303 (3.38 mmol g–1),36BSF-2 (0.79 mmol g–1),53 and 0.3Gly@HKUST-1 (4.22 mmol g–1).32 That the C3H8 isotherm is much steeper than the C2H6 and CH4 isotherms suggests that sorbate–sorbent interactions increase from CH4 to C2H6 to C3H8, as expected from their sizes and polarizabilities. To further explore the affinity of CMOM-7 toward pure gases, the single-component adsorption isotherms of CH4 and C2H6 were fitted using the single-site Langmuir Freundlich (SSLF) model (Figures S18, S19), and those of C3H8 were fitted to the dual-site Langmuir Freundlich (DSLF) model (Figure S20, Tables S4 and S5). From the pure gas isotherms recorded at 273, 298, and 313 K, the corresponding isosteric enthalpies of adsorption (Qst) values at low surface coverage were determined to be 20.9, 27.9, and 31.2 kJ mol–1, respectively (Figure 2c), once again indicating that CMOM-7 exhibits stronger affinity for C3H8 than C2H6 and CH4.

Ideal adsorbed solution theory (IAST) selectivity values for binary mixtures C3H8/C2H6, C2H6/CH4, and C3H8/CH4 were calculated from the 298 K pure gas isotherms. The IAST selectivities for C3H8/CH4 (5:85 and 1:1), C3H8/C2H6 (5:10 and 1:1), and C2H6/CH4 (10:85 and 1:1) at 1 bar were found to be 151.4, 40.1 (C3H8/CH4), 13.6, 13.3 (C3H8/C2H6), 17.1 and 12.5 (C2H6/CH4) (Figures 2d and S21). The boiling points for CH4, C2H6, and C3H8, 111.6, 184.6, and 231 K, respectively, are consistent with the general expectation that IAST selectivities correlate with adsorbate boiling points. These IAST selectivities indicate potential for ternary mixture recovery of C3H8 from CH4 and C2H6, being competitive for both C3H8/CH4 and C3H8/C2H6 (Figure 2e,f and Table S8). Specifically, whereas the C3H8/CH4 (5:85) IAST selectivity for CMOM-7 exceeds that of MIL-100(Fe) (33.3),37MIL-101-Fe-NH2 (42.5),40Zn-BPZ-SA (65.7),38Fe-pyz (89),54 it is lower than that of MOF-303 (5114),36Ni(TMBDC)(DABDC)0.5 (274),34CFA-1-NiCl2-2.3 (382.7),55 and ZUL-C2 (741).56 The C3H8/C2H6 (1:1) IAST selectivity of CMOM-7 exceeds ECUT-Th-10 (9.31),39UiO-67 (∼9.5),39MFM-202a (∼7),57NIIC-20-Bu (10.4),41 and Ni2(L)2(HCOO)2(H2O)4 (L = 3-hydroxy-4-(4H-1,2,4-triazol-4-yl)benzoate)58 but is lower than NIIC-20-Et (29.0),41NIIC-20-Pr (28.0),41 and NIIC-20-Gl (25.2).41

To determine the separation performance, DCB experiments of binary mixtures were performed under ambient conditions. For C3H8/CH4 (v/v = 5:85, total flow = 9 mL min–1) and C2H6/CH4 (v/v = 10:85, total flow = 9.5 mL min–1), CH4 was found to elute immediately, whereas C3H8 and C2H6 eluted at 108 and 11.4 min g–1, respectively (Figures 3a and S24). For C3H8/C2H6 (v/v = 5:10, 1.5 mL min–1), C2H6 and C3H8 eluted at 34.1 and 119.3 min g–1, respectively (Figure 3b). CMOM-7 adsorbed 72.7 mL g–1 (3.24 mmol g–1) C3H8 and 3.9 mL g–1 (0.17 mmol g–1) C2H6, resulting in C3H8/C2H6 selectivity of 37.3. We next conducted DCB experiments on a ternary C3H8/C2H6/CH4 (v/v/v = 5:10:85) mixture with a total flow of 10 mL min–1. CH4 eluted immediately and 3.4 mmol g–1 of high-purity CH4 (≥98%) was produced before C2H6 and C3H8 passed through the fixed bed at 11.4 min g–1 and 90.9 min g–1, respectively (Figure 3c). The breakthrough time difference (Δt) between C3H8 and C2H6 was 79.5 min g–1. To the best of our knowledge, this Δt value exceeds MOFs studied with the same ternary mixture and flow rate (Figure 3d and Table S9): SNNU-Bai-68 (49 min g–1),33SNNU-Bai78 (40.3 min g–1),590.3Gly@HKUST-1 (66 min g–1),32HKUST-1 (67 min g–1),32MOF-801 (15.72 min g–1),60MIL-142A (55 min g–1),61 and BSF-1 (30.1 min g–1),62 inter alia. During the DCB experiment, 0.48 mmol g–1 C2H6 and 2.45 mmol g–1 C3H8 were found to be absorbed by CMOM-7 (Table S6). The dynamic uptake of C3H8 exceeded several NG separating sorbents including BSF-2 (∼0.76 mmol g–1),53C-PVDC-800 (3.02 mmol g–1),63ZUL-C1 (1.90 mmol g–1),56ZUL-C2 (1.92 mmol g–1),56 and MIL-101-Cr (0.60 mmol g–1).40

Figure 3.

Figure 3

Open in a new tab

Breakthrough study results on CMOM-7 for CH4, C2H6 and C3H8 gas mixtures at 298 K and 1 bar. (a) The breakthrough profiles for C3H8/CH4 (v/v = 5:85, 9 mL min–1) gas mixture. (b) The breakthrough profiles for C3H8/C2H6 (v/v = 5:10, 1.5 mL min–1) gas mixture. (c) The breakthrough profiles for C3H8/C2H6/CH4 (v/v/v = 5:10:85, 10 mL min–1) gas mixture. (d) For the C3H8/C2H6/CH4 (v/v/v = 5:10:85, 10 mL min–1) DCB experiments, performance comparison of CMOM-7 with reported materials on their relative CH4, C2H6, and C3H8 breakthrough times; and their breakthrough time differences (Δt) (between C3H8 and C2H6). (e) Temperature-programmed desorption profiles recorded under 50 mL min–1 He flow after the C3H8/C2H6/CH4 (v/v/v = 5:10:85, 10 mL min–1) ternary mixture breakthrough experiment-based bed saturation. (f) Gravimetric adsorption kinetics for CH4, C2H6 and C3H8 on CMOM-7, plotted as uptake (wt %) vs time (min).

The CMOM-7 packed column was regenerated by using a helium flow (50 mL min–1). As revealed by Figure 3e, CH4 and C2H6 were removed within 11.4 min g–1, while C3H8 took 360 min g–1 (Figure 3e). 1.6 mmol g–1 high-purity (≥98%) C3H8 was obtained during the interim period (39.8 to 221.6 min g–1). The stability of the packed column was investigated by DCB cycling under identical conditions (Figure S25). Breakthrough times and dynamic uptakes remained almost unchanged over three cycles (Table S6). We also studied DCB performance with total flow rates of 9, 11, and 12 mL min–1 (Figure S26). CH4 always eluted immediately; breakthrough times for C2H6 were 11.4 min g–1 at 9 mL min–1 and 5.7 min g–1 at 11 and 12 mL min–1. Under flow rates of 9, 10, and 12 mL min–1, breakthrough times for C3H8 were 102.3, 85.2, and 79.5 min g–1, respectively.

Adsorption kinetics for CH4, C2H6 and C3H8 were assessed by exposing CMOM-7 to 10 mL min–1 flows of CH4, C2H6 and C3H8 at 303 K and 1 bar, separately. CMOM-7 adsorbed 0.29 wt % (0.18 mmol g–1) of CH4 in 5 min, and 3.67 wt % (1.22 mmol g–1) of C2H6 in 10 min. 10.88 wt % (2.48 mmol g–1) of C3H8 was adsorbed in 20 min (Figure 3f). Consistent kinetic results over three consecutive sorption cycles were found (Figure S10). Adsorption kinetics for C3H8 and C2H6 exhibited similar slopes at low loading, suggesting that the separation performance is not driven by kinetics alone. Nevertheless, under an identical flow rate and other conditions, CMOM-7 adsorbed a higher amount of C3H8 than C2H6. This suggests that the C3H8 selectivity is driven by a combination of optimal thermodynamics and kinetics, a phenomenon we have previously observed in ultramicroporous sorbents that exhibit benchmark CO2 and C2 trace capture.28,64,65

To assess hydrolytic stability, crystals of CMOM-7-MeOH were soaked in water for a day (Figure S1). Water molecules exchanged with methanol molecules, affording the water-loaded structure {[Ni(S-IDEC)(bipy)(SCN)](H2O)6.5}n, CMOM-7-H2O, as determined by SCXRD. CMOM-7-H2O crystallized in space group C2221 (Table S2). PXRD patterns (Figure S7) verified the stability in water and at 75% relative humidity (RH). CMOM-7 did not change structure after solvent exchange (Figure S3). TGA data revealed weight loss of 17.62 wt % at 63 °C (Figure S9).

Seven water binding sites were identified in CMOM-7-H2O, interacting with the pore walls through O–H···O and O–H···S hydrogen bonds (H-bonds) involving the O atoms of S-IDEC and S atoms of SCN– ligands (Figure S4). The dynamic vapor sorption (DVS) H2O isotherm for CMOM-7 exhibited a sigmoidal S shape (Figure S28)44 with low uptake of water (1.56 wt %) at 30% RH followed by hysteresis and uptake of 20.19 and 23.94 wt % at 55% RH and 95% RH, respectively. The water adsorption kinetics revealed that CMOM-7 had uptake of 22.5 wt % within 40 min at 60% RH (Figure S29). Water vapor sorption cycling was also conducted. In the first cycle, CMOM-7 exhibited an uptake of 19.29 wt % at 60% RH in 25 min and uptake of 18.35 wt % at the tenth cycle (Figure S30a). After 100 cycles, uptake had dropped to 14.69 wt % (Figure S30b), indicating partial collapse of CMOM-7. A water-soaked sample of CMOM-7 exhibited an uptake of 3.31 mmol g–1, similar to pristine CMOM-7 (3.4 mmol, Figures 2b and S13).

To gain insight into the C3H8-selective nature of CMOM-7, we obtained its C3H8 loaded structure using a C3H8 loaded Schlenk bottle at 195 K for 12 h (bath of dry ice) which enabled CMOM-7 crystals to equilibrate. SCXRD study of the resulting phase allowed us to determine the crystal structure of the corresponding C3H8 loaded phase, {[Ni(S-IDEC)(bipy)(SCN)](C3H8)1.5}n, CMOM-7-C3H8, which had crystallized in the orthorhombic spaced group C2221 (Table S2). PXRD diffractograms (Figure S6) confirmed the phase purity and crystallinity. The asymmetric unit comprised 1.5 molecules of C3H8, with C3H8 uptake at 273 K (3.44 mmol g–1) matching the composition of CMOM-7-C3H8 (3.45 mmol g–1). Two C3H8 molecules were observed in the asymmetric unit at sites I and II (Figure 4). Cambridge Structural Database (CSD) mining revealed that this is only the tenth example of ordered C3H8 molecules determined by SCXRD (Figure S27 and Table S7). As shown in Figure 4a, C3H8 molecules in binding site I are 2-fold disordered in a ratio of 1:1 around an inversion center.66 Site I molecules forms C–H···π interactions with the pyridine rings of bipy linkers (3.24–3.91 Å, Figure 4b). The molecule in binding site II is also 2-fold disordered, with occupancies of 0.68 and 0.32 for A and B, respectively. A interacts with the host framework through C–H···π interactions on the pyridine ring of bipy (3.76–3.85 Å) and the C=N bond of the SCN– ligands (3.11 Å, Figure 4c). B interacts with a) the S atoms of SCN– through H-bond interactions (3.71 Å); b) the edges of the pyridine rings of bipy; and c) phenyl rings of S-IDEC through C–H···π interactions (3.22–3.99 Å, Figure 4d).

Figure 4.

Figure 4

Open in a new tab

Crystallographically determined binding site of C3H8 molecules along the channel of CMOM-7 (a) and the intermolecular interactions between C3H8 molecules and the host framework of CMOM-7 around site-I (b), site-II part A (c) and site-II part B (c). Atoms of C3H8 in binding site-I are colored in orange, whereas atoms of C3H8 in binding site-II part A and site-II part B are colored pink and dark yellow, respectively. The C–H···π interactions are represented by blue dashed lines, and the H-bond is represented by a red dashed line. All distances are given in Angstrom units.

Grand Canonical Monte Carlo (GCMC) simulations and first-principles density functional theory (DFT) calculations were conducted to determine the binding sites and energies in CMOM-7.67 The CH4 binding site was observed to have C–H···π interactions with a) the edges of bipy-1 pyridine rings (2.89–3.25 Å); and b) the SC bond of SCN– (3.63 Å, Figure 5a), resulting in a CH4 binding energy of 14.2 kJ mol–1. The C2H6 binding site featured stronger interactions with CMOM-7 through C–H···π interactions with a) bipy pyridine rings (3.46–3.86 Å) and b) the SC bonds of SCN– ligands (3.93 Å, Figure 5b). The C2H6 binding energy was calculated to be 25.7 kJ mol–1. For C3H8, two binding sites were identified, where the second site revealed two orientations (Figures 5c,d and S31). Site-I interacts with the pyridine rings of bipy ligands through C–H···π interactions (3.24–3.99 Å, Figure 5c). Site-II interacts through the S atoms of SCN– forming H-bonds (3.72 Å), and the benzene rings of S-IDEC (3.08–3.99 Å, Figure 5d). The C3H8 binding energies with CMOM-7 in sites-I and II were determined to be 38.5 and 31.1 kJ mol–1, respectively. The modeled binding sites were found to be in agreement with site-I and part-B of site-II in the SCXRD determined crystal structure of CMOM-7-C3H8 (Figure 4). Moreover, the calculated binding energies fit the trend indicated by the experimental Qst trends (Figure 2c).

Figure 5.

Figure 5

Open in a new tab

Binding sites of CH4 (a), C2H6 (b) and C3H8 (c, d) molecules along the ultramicroporous channel of CMOM-7, determined by GCMC calculations. CH4 and C2H6 molecules are colored mauve and light green, respectively, whereas the C3H8 molecules residing in sites I and II are presented in orange and dark yellow, respectively. C–H···π interactions are represented by blue dashed lines, whereas the H-bond is represented by a red dashed line. All distances are given Angstrom units.

In this work, a novel lon topology ultramicroporous MOF, CMOM-7, is reported. The ultramicroporosity and pore chemistry of CMOM-7 was found to exhibit stronger affinity toward C3H8 vs both C2H6 and CH4, leading to high-purity C3H8 production from a ternary C3H8/C2H6/CH4 (v/v/v = 5:10:85) gas mixture. DCB experiments revealed high C3H8 uptake (2.45 mmol g–1), high C3H8/C2H6 selectivity (10.1) and a long breakthrough time difference, Δt (79.5 min g–1) between C3H8 and C2H6. SCXRD analysis of the propane binding sites in CMOM-7 channels and complementary modeling studies of the C3H8 binding sites indicate that multiple weak intermolecular interactions are the key to the observed separation performance. That CMOM-7 exhibited stronger intermolecular interactions with C3H8 molecules over C2H6 and CH4 is key to its high C3H8 selectivity even under ternary mixture compositions, in turn leading to the benchmark breakthrough time difference, Δt. In this context, CMOM-7 outperforms previously studied MOFs under equivalent experimental conditions. The approach taken herein, systematic crystal engineering of ultramicroporous coordination networks to fine-tune pore size, shape, and chemistry, suggests that more energy-efficient approaches to purification of commodity chemicals will ultimately come to fruition.

Acknowledgments

We gratefully acknowledge support from the Irish Research Council (IRCLA/2019/167), European Research Council (ADG 885695) and Science Foundation Ireland (13/RP/B2549 and 16/IA/4624). S.M. acknowledges an SFI-IRC Pathway award (21/PATH-S/9454) from the Science Foundation Ireland. Y.-L.P. acknowledges National Natural Science Foundation of China (No. 22201304) and the Science Foundation of China University of Petroleum, Beijing (2462021QNXZ011).

Glossary

ABBREVIATIONS

NG

natural gas

CH4

methane

C2H6

ethane

C2H4

ethylene

C2H2

acetylene

C3H8

propane

C3H6

propylene

C3H4

methyl acetylene

SCXRD

single-crystal X-ray diffraction

MOMs

metal–organic materials

MOFs

metal–organic frameworks

PCPs

porous coordination polymers

PCNs

porous coordination networks

CMOMs

chiral metal–organic materials

S-IDEC

S-indoline-2-carboxylicate

RBB

rod building block

bipy

4,4′-bipyridine

CCSs

chiral crystalline sponges

CSD

Cambridge, structural database

PXRD

powder X-ray diffraction

VT-PXRD

variable temperature powder X-ray diffraction

TGA

thermogravimetric analyses

DMF

N,N-dimethylformamide

SSLF

single-site Langmuir Freundlich

BET

Brunauer–Emmett–Teller

DSLF

Double-site Langmuir Freundlich

Qst

isosteric enthalpy of adsorption

IAST

ideal adsorption solution theory

DCB

dynamic column breakthrough

GC

gas chromatography

FID

flame ionization detector

TCD

thermal conductivity detector

Δt

breakthrough time difference

DVS

dynamic vapor sorption

H-bond

hydrogen bond

GCMC

Grand Canonical Monte Carlo

DFT

density field theory

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsmaterialslett.3c01157.

  • Experimental details, supplementary characterization results, additional figures, data analysis, and computational calculations (PDF)

  • AIF files (ZIP)

  • X-ray data for CMOM-7-C3H8 (CIF)

  • X-ray data for CMOM-7-DMF (CIF)

  • X-ray data for CMOM-7-H2O (CIF)

  • X-ray data for CMOM-7-MeOH (CIF)

  • X-ray data for CMOM-7-vac (CIF)

Author Contributions

C.D. conducted the materials design and syntheses. The gas sorption experiments, and related analyses were conducted by C.D., B.-Q.S., D.S., and S.M. The gas separation experiments and kinetic sorption studies were conducted by M.-Y.G., C.D., Y.-L.P., and S.M. Water vapor sorption studies were conducted by S. D. Crystallographic analysis were conducted by C.D., M.-Y.G., and M.L. Modeling studies were conducted by Z.L. and Y.-L.P. First draft of the manuscript was written by C. D., S.M., and M.J.Z., whereas all authors have contributed to approving the final version. Li Zhao helped with investigation. CRediT: Zhao Li investigation.

The authors declare no competing financial interest.

Supplementary Material

tz3c01157_si_001.pdf (4.6MB, pdf)
tz3c01157_si_002.zip (8.9MB, zip)
tz3c01157_si_003.cif (841.7KB, cif)
tz3c01157_si_004.cif (1.8MB, cif)
tz3c01157_si_005.cif (684.2KB, cif)
tz3c01157_si_006.cif (1.4MB, cif)
tz3c01157_si_007.cif (1.8MB, cif)

References

  1. Westbrook S. R.; Shah R. J.. Fuels and Lubricants Handbook: Technology, Properties, Performance, and Testing; ASTM International, 2003. [Google Scholar]
  2. Raslavičius A.; Keršys A.; Mockus S.; Keršienė N.; Starevičius M. Liquefied Petroleum Gas (LPG) as a Medium-Term Option in the Transition to Sustainable Fuels and Transport. Renew. Sust. Energy Rev. 2014, 32, 513–525. 10.1016/j.rser.2014.01.052. [DOI] [Google Scholar]
  3. Mortazavi A.; Somers C.; Hwang Y.; Radermacher R.; Rodgers P.; Al-Hashimi S. Performance Enhancement of Propane Pre-Cooled Mixed Refrigerant LNG Plant. Appl. Energy 2012, 93, 125–131. 10.1016/j.apenergy.2011.05.009. [DOI] [Google Scholar]
  4. Harby K. Hydrocarbons and Their Mixtures as Alternatives to Environmental Unfriendly Halogenated Refrigerants: An Updated Overview. Renew. Sust. Energy Rev. 2017, 73, 1247–1264. 10.1016/j.rser.2017.02.039. [DOI] [Google Scholar]
  5. Chen S.; Chang X.; Sun G.; Zhang T.; Xu Y.; Wang Y.; Pei C.; Gong J. Propane Dehydrogenation: Catalyst Development, New Chemistry, and Emerging Technologies. Chem. Soc. Rev. 2021, 50, 3315–3354. 10.1039/D0CS00814A. [DOI] [PubMed] [Google Scholar]
  6. Ren B.; Patel M.; Blok K. Olefins from Conventional and Heavy Feedstocks: Energy Use in Steam Cracking and Alternative Processes. Energy 2006, 31, 425–451. 10.1016/j.energy.2005.04.001. [DOI] [Google Scholar]
  7. Mishra N.; Boeckl J.; Motta N.; Iacopi F. Graphene Growth on Silicon Carbode: A Review. Phys. Status Solidi A 2016, 213, 2277–2289. 10.1002/pssa.201600091. [DOI] [Google Scholar]
  8. Nishizawa B.-i.; Pons M. Growth and Doping Modeling of SiC-CVD in a Horizontal Hot-Wall Reactor. Chem. Vap. Deposition 2006, 12, 516–522. 10.1002/cvde.200606469. [DOI] [Google Scholar]
  9. Speight J. G.; Özüm B.. Petrolwum Refining Process; Marcel Dekker, 2002. [Google Scholar]
  10. Kidnay A. J.; Parrish W. R.; McCartney D. G.. Fundamentals of Natural Gas Processing, 3rd ed.; CRC Press, 2020. [Google Scholar]
  11. Mazyan W.; Ahmadi A.; Ahmed H.; Hoorfar M. Market and Technology Assessment of Natural Gas Processing: A Review. J. Nat. Gas. Sci. Eng. 2016, 30, 487–514. 10.1016/j.jngse.2016.02.010. [DOI] [Google Scholar]
  12. Zhao H.; Sun M.; Firoozabadi A. Anti-Agglomeration of Natural Gas Hydrates in Liquid Condensate and Crude Oil at Constant Pressure Conditions. Fuel 2016, 180, 187–193. 10.1016/j.fuel.2016.03.029. [DOI] [Google Scholar]
  13. (accessed Mar. 7, 2023)
  14. Ghosh T. K.; Lin H.-D.; Hines A. L. Hybrid Adsorption-Distillation Process for Separating Propane and Propylene. Ind. Eng. Chem. Res. 1993, 32, 2390–2399. 10.1021/ie00022a024. [DOI] [Google Scholar]
  15. De Guido G.; Lange S.; Pellegrini L. A. Refrigeration Cycles in Low-Temperature Distillation Processes for the Purification of Natural Gas. J. Nat. Gas Sci. Eng. 2015, 27, 887–900. 10.1016/j.jngse.2015.09.041. [DOI] [Google Scholar]
  16. Sholl D. S.; Lively R. P. Seven Chemical Separations to Change the World. Nature 2016, 532, 435–437. 10.1038/532435a. [DOI] [PubMed] [Google Scholar]
  17. Sivakumar S. V.; Rao D. P. Adsorptive Separation of Gas Mixtures: Mechanistic View, Sharp Separation and Process Intensification. Chem. Eng. Process. 2012, 53, 31–52. 10.1016/j.cep.2011.12.012. [DOI] [Google Scholar]
  18. Zhao X.; Wang Y.; Li D.-S.; Bu X.; Feng P. Metal-Organic Frameworks for Separation. Adv. Mater. 2018, 30, 1705189 10.1002/adma.201705189. [DOI] [PubMed] [Google Scholar]
  19. Gao M.-Y.; Song B.-Q.; Sensharma D.; Zaworotko M. J. Crystal Engineering of Porous Coordination Networks for C3 Hydrocarbon Separation. SmartMat 2021, 2, 38–55. 10.1002/smm2.1016. [DOI] [Google Scholar]
  20. Lin R.-B.; Xiang S.; Zhou W.; Chen B. Microporous Metal-organic Framework Materials for Gas Separation. Chem. 2020, 6, 337–363. 10.1016/j.chempr.2019.10.012. [DOI] [Google Scholar]
  21. Yang L.; Qian S.; Wang X.; Cui X.; Chen B.; Xing H. Energy-efficient Separation Alternatives: Metal–organic Frameworks and Membranes for Hydrocarbon Separation. Chem. Soc. Rev. 2020, 49, 5359–5406. 10.1039/C9CS00756C. [DOI] [PubMed] [Google Scholar]
  22. Perry J. J. IV; Perman J. A.; Zaworotko M. J. Design and Synthesis of Metal–organic Frameworks Using Metal–organic Polyhedra as Supermolecular Building Blocks. Chem. Soc. Rev. 2009, 38, 1400. 10.1039/b807086p. [DOI] [PubMed] [Google Scholar]
  23. Kitagawa S.; Kitaura R.; Noro S.-I. Functional Porous Coordination Polymers. Angew. Chem., Int. Ed. 2004, 43, 2334–2375. 10.1002/anie.200300610. [DOI] [PubMed] [Google Scholar]
  24. Schröder M.Functional Metal-Organic Frameworks: Gas Storage, Separation and Catalysis; Springer-Verlag, 2010. [Google Scholar]
  25. MacGillivray L. R.Metal–Organic Frameworks: Design and Application; John Wiley & Sons, 2010. [Google Scholar]
  26. Moulton B.; Zaworotko M. J. From Molecules to Crystal Engineering: Supramolecular Isomerism and Polymorphism in Network Solids. Chem. Rev. 2001, 101, 1629–1658. 10.1021/cr9900432. [DOI] [PubMed] [Google Scholar]
  27. Mukherjee S.; Zaworotko J. M. Crystal Engineering of Hybrid Coordination Networks: from Form to Function. Trends Chem. 2020, 2, 506–518. 10.1016/j.trechm.2020.02.013. [DOI] [Google Scholar]
  28. Nugent P.; Belmabkhout Y.; Burd S. D.; Cairns A. J.; Luebke R.; Forrest K.; Pham T.; Ma S.; Space B.; Wojtas L.; Eddaoudi M.; Zaworotko M. J. Porous Materials with Optimal Adsorption Thermodynamics and Kinetics for CO2 Separation. Nature 2013, 495, 80–84. 10.1038/nature11893. [DOI] [PubMed] [Google Scholar]
  29. Mukherjee S.; Sensharma D.; Chen K.-J.; Zaworotko M. J. Crystal Engineering of Porous Coordination Networks to Enable Separation of C2 Hydrocarbons. Chem. Commun. 2020, 56, 10419–10441. 10.1039/D0CC04645K. [DOI] [PubMed] [Google Scholar]
  30. Li J.-R.; Sculley J.; Zhou H.-C. Metal-Organic Frameworks for Separations. Chem. Rev. 2012, 112, 869–932. 10.1021/cr200190s. [DOI] [PubMed] [Google Scholar]
  31. Li J.-R.; Kuppler R. J.; Zhou H.-C. Selective Gas Adsorption and Separation in Metal–organic Frameworks. Chem. Soc. Rev. 2009, 38, 1477. 10.1039/b802426j. [DOI] [PubMed] [Google Scholar]
  32. Wu Y.; Sun Y.; Xiao J.; Wang X.; Li Z. Glycine-modified HKUST-1 with Simultaneously Enhanced Moisture Stability and Improved Adsorption for Light Hydrocarbons Separation. ACS Sustainable Chem. Eng. 2019, 7, 1557–1563. 10.1021/acssuschemeng.8b05321. [DOI] [Google Scholar]
  33. Cheng H.; Wang Q.; Meng L.; Sheng P.; Zhang Z.; Ding M.; Gao Y.; Bai J. Formation of a N/O/F-Rich and Rooflike Cluster-Based Highly Stable Cu(I/II)-MOF for Promising Pipeline Natural Gas Upgrading by the Recovery of Individual C3H8 and C2H6 Gases. ACS Appl. Mater. Interfaces 2021, 13, 40713–40723. 10.1021/acsami.1c11971. [DOI] [PubMed] [Google Scholar]
  34. Wu Y.; Liu Z.; Peng J.; Wang X.; Zhou X.; Li Z. Enhancing Selective Adsorption in a Robust Pillared-Layer Metal–Organic Framework via Channel Methylation for the Recovery of C2–C3 from Natural Gas. ACS Appl. Mater. Interfaces 2020, 12, 51499–51505. 10.1021/acsami.0c15267. [DOI] [PubMed] [Google Scholar]
  35. Zheng F.; Chen R.; Zhang Z.; Yang Q.; Yang Y.; Ren Q.; Bao Z. Cooperative Control of Intralayer and Interlayer Space in MOFs Enables Selective Capture of Intermediate-sized Molecules. Cell Rep. Phys. Sci. 2022, 3, 100903 10.1016/j.xcrp.2022.100903. [DOI] [Google Scholar]
  36. Xian S.; Peng J.; Pandey H.; Thonhauser T.; Wang H.; Li J. Robust Metal–Organic Frameworks with High Industrial Applicability in Efficient Recovery C3H8 and C2H6 from Natural Gas Upgrading. Engineering 2023, 23, 56–63. 10.1016/j.eng.2022.07.017. [DOI] [Google Scholar]
  37. Yuan B.; Wang X.; Zhou X.; Xiao J.; Li Z. Novel Room-Temperature Synthesis of MIL-100(Fe) and its Excellent Adsorption Performances for Separation of Light Hydrocarbons. Chem. Eng. J. 2019, 355, 679–686. 10.1016/j.cej.2018.08.201. [DOI] [Google Scholar]
  38. Wang G.-D.; Krishna R.; Li Y.-Z.; Ma Y.-Y.; Hou L.; Wang Y.-Y.; Zhu Z. Rational Construction of Ultrahigh Thermal Stable MOF for Efficient Separation of MTO Products and Natural Gas. ACS Materials Lett. 2023, 5, 1091–1099. 10.1021/acsmaterialslett.3c00096. [DOI] [Google Scholar]
  39. Wang L.; Zhang W.; Ding J.; Gong L.; Krishna R.; Ran Y.; Chen L.; Luo F. Th-MOF Showing Six-fold Imide-Sealed Pockets for Middle-Size-Separation of Propane from Natural Gas. Nano Res. 2023, 16, 3287–3293. 10.1007/s12274-022-4915-0. [DOI] [Google Scholar]
  40. Qin L.-Z.; Xiong X.-H.; Wang S.-H.; Zhang L.; Meng L.-L.; Yan L.; Fan Y.-N.; Yan T.-A.; Liu D.-H.; Wei Z.-W.; Su C.-Y. MIL-101-Cr/Fe/Fe-NH2 for Efficient Separation of CH4 and C3H8 from Simulated Natural Gas. ACS Appl. Mater. Interfaces 2022, 14, 45444–45450. 10.1021/acsami.2c13446. [DOI] [PubMed] [Google Scholar]
  41. Lysova A. A.; Kovalenko K. A.; Nizovtsev A. S.; Dybtsev D. N.; Fedin V. P. Efficient separation of methane, ethane and propane on mesoporous metal-organic frameworks. Chem. Eng. J. 2023, 453, 139642 10.1016/j.cej.2022.139642. [DOI] [Google Scholar]
  42. Zhang S.-Y.; Wojtas L.; Zaworotko M. J. Structural Insight into Guest Binding Sites in a Porous Homochiral Metal-Organic Material. J. Am. Chem. Soc. 2015, 137, 12045–12049. 10.1021/jacs.5b06760. [DOI] [PubMed] [Google Scholar]
  43. Zhang S.-Y.; Yang C.-X.; Shi W.; Yan X.-P.; Cheng P.; Wojtas L.; Zaworotko M. J. A Chiral Metal-Organic Material that Enables Enantiomeric Identification and Purification. Chem. 2017, 3, 281–289. 10.1016/j.chempr.2017.07.004. [DOI] [Google Scholar]
  44. Zhang S.-Y.; Jensen S.; Tan K.; Wojtas L.; Roveto M.; Cure J.; Thonhauser T.; Chabal Y. J.; Zaworotko M. J. Modulation of Water Vapor Sorption by a Fourth-Generation Metal–Organic Material with a Rigid Framework and Self-Switching Pores. J. Am. Chem. Soc. 2018, 140, 12545–12552. 10.1021/jacs.8b07290. [DOI] [PubMed] [Google Scholar]
  45. Zhang S.-Y.; Fairen-Jimenez D.; Zaworotko M. J. Structural Elucidation of the Mechanism of Molecular Recognition in Chiral Crystalline Sponges. Angew. Chem., Int. Ed. 2020, 59, 17600–17606. 10.1002/anie.202006438. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Deng C.; Song B.-Q.; Lusi M.; Bezrukov; Haskins M. M.; Gao M.-Y.; Peng Y.-L.; Ma J.; Cheng P.; Mukherjee S.; Zaworotko M. J. Crystal Engineering of a Chiral Crystalline Sponge That Enables Absolute Structure Determination and Enantiomeric Separation. Cryst. Growth Des. 2023, 23, 5211–5220. 10.1021/acs.cgd.3c00446. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Singh P. P.; Singh V. P.; Khan M. U.; Singh D. Reaction of Amylmercury Thiocyanate with Thio and Selenocyanates of Co(II), Ni(II) and Zn(II). Synth. React. Inorg. M. 1984, 14, 111–128. 10.1080/00945718408057516. [DOI] [Google Scholar]
  48. Gao M.-Y.; Bezrukov A. A.; Song B.-Q.; He M.; Nikkhah S. J.; Wang S.-Q.; Kumar N.; Darwish S.; Sensharma D.; Deng C.; Li J.; Liu L.; Krishna R.; Vandichel M.; Yang S.; Zaworotko M. J. Highly Productive C3H4/C3H6 Trace Separation by a Packing Polymorph of a Layered Hybrid Ultramicroporous Material. J. Am. Chem. Soc. 2023, 145, 11837–11745. 10.1021/jacs.3c03505. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Ingleson M. J.; Bacsa J.; Rosseinsky M. J. Homochiral H-Bonded Proline Based Metal Organic Frameworks. Chem. Commun. 2007, 3036–3038. 10.1039/b706557d. [DOI] [PubMed] [Google Scholar]
  50. (accessed May 29, 2023)
  51. (accessed May 29, 2023)
  52. Thommes M.; Kaneko K.; Neimark A. V.; Olivier J. P.; Rodriguez-Reinoso F.; Rouquerol J.; Sing K. S.W. Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure Appl. Chem. 2015, 87, 1051–1069. 10.1515/pac-2014-1117. [DOI] [Google Scholar]
  53. Zhang Y.; Yang Li.; Wang L.; Cui X.; Xing H. Pillar Iodination in Functional Boron Cage Hybrid Supramolecular Frameworks for High Performance Separation of Light Hydrocarbons. J. Mater. Chem. A 2019, 7, 27560–27566. 10.1039/C9TA09928J. [DOI] [Google Scholar]
  54. Zhao L.; Liu P.; Deng C.; Wang T.; Wang S.; Tian Y.-J.; Zou J.-S.; Wu X.-C.; Zhang Y.; Peng Y.-L.; Zhang Z.; Zaworotko M. J. Robust Ultra-microporous Metal-organic Frameworks for Highly Efficient Natural Gas Purification. Nano Res. 2023, 16, 12338–12344. 10.1007/s12274-023-6072-5. [DOI] [Google Scholar]
  55. Peng J.; Zhong J.; Liu Z.; Xi H.; Yan J.; Xu F.; Chen X.; Wang X.; Lv D.; Li Z. Multivariate Metal–organic Frameworks Prepared by Simultaneous Metal/ligand Exchange for Enhanced C2–C3 Selective Recovery from Natural Gas. ACS Appl. Mater. Interfaces 2023, 15, 41466–41475. 10.1021/acsami.3c06663. [DOI] [PubMed] [Google Scholar]
  56. Zhou J.; Ke T.; Steinke F.; Stock N.; Zhang Z.; Bao Z.; He X.; Ren Q.; Yang Q. Tunable Confined Aliphatic Pore Environment in Robust Metal–Organic Frameworks for Efficient Separation of Gases with a Similar Structure. J. Am. Chem. Soc. 2022, 144, 14322–14329. 10.1021/jacs.2c05448. [DOI] [PubMed] [Google Scholar]
  57. Gao S.; Morris C. G.; Lu Z.; Yan Y.; Godfrey H. G. W.; Murray C.; Tang C. C.; Thomas K. M.; Yang S.; Schroder M. Selective Hysteretic Sorption of Light Hydrocarbons in a Flexible Metal–Organic Framework Material. Chem. Mater. 2016, 28, 2331–2340. 10.1021/acs.chemmater.6b00443. [DOI] [Google Scholar]
  58. Zhang X.-X.; Guo X.-Z.; Chen S.-S.; Kang H.-W.; Zhao Y.; Gao J.-X.; Xiong G.-Z.; Hou L. A stable microporous framework with multiple accessible adsorption sites for high capacity adsorption and efficient separation of light hydrocarbons. Chem. Eng. J. 2023, 466, 143170 10.1016/j.cej.2023.143170. [DOI] [Google Scholar]
  59. Cheng H.; Wang Q.; Bai J. Ligand-functional Groups Induced Tuning MOFs’ 2D into 1D Pore Channels for Pipeline Natural Gas Purification. Chem.—Eur. J. 2023, 29, e202202047 10.1002/chem.202202047. [DOI] [PubMed] [Google Scholar]
  60. Liu H.; Li B.; Zhao Y.; Kong C.; Zhou C.; Lin Y.; Tian Z.; Chen L. Investigation on a Zr-based Metal–Organic Framework (MOF-801) for the High-Performance Separation of Light Alkanes. Chem. Commun. 2021, 57, 13008–13011. 10.1039/D1CC05306J. [DOI] [PubMed] [Google Scholar]
  61. Yuan Y.; Wu H.; Xu Y.; Lv D.; Tu S.; Wu Y.; Li Z.; Xia Q. Selective Extraction of Methane from C1/C2/C3 on Moisture-Resistant MIL-142A with Interpenetrated Networks. Chem. Eng. J. 2020, 395, 125057 10.1016/j.cej.2020.125057. [DOI] [Google Scholar]
  62. Zhang Y.; Yang L.; Wang L.; Duttwyler S.; Xing H. A Microporous Metal-Organic Framework Supramolecularly Assembled from a CuII Dodecaborate Cluster Complex for Selective Gas Separation. Angew. Chem., Int. Ed. 2019, 58, 8145–8150. 10.1002/anie.201903600. [DOI] [PubMed] [Google Scholar]
  63. Chen F.; Guo K.; Huang X.; Zhang Z.; Yang Q.; Yang Y.; Ren Q.; Bao Z. Extraction of Propane and Ethane from Natural Gas on Ultramicroporous Carbon Adsorbent with Record Selectivity. Sci. China Mater. 2023, 66, 319–326. 10.1007/s40843-022-2096-8. [DOI] [Google Scholar]
  64. Cui X.; Chen K.; Xing H.; Yang Q.; Krishna R.; Bao Z.; Wu H.; Zhou W.; Dong X.; Han Y.; Li B.; Ren Q.; Zaworotko M. J.; Chen B. Pore chemistry and size control in hybrid porous materials for acetylene capture from ethylene. Science 2016, 353, 141–144. 10.1126/science.aaf2458. [DOI] [PubMed] [Google Scholar]
  65. Cao J.-W.; Mukherjee S.; Pham T.; Wang Y.; Wang T.; Zhang T.; Jiang X.; Tang H.-J.; Forrest K. A.; Space B.; Zaworotko M. J.; Chen K.-J. One-step Ethylene Production from a Four-component Gas Mixture by a Single Physisorbent. Nat. Commun. 2021, 12, 6507. 10.1038/s41467-021-26473-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Müller P.Disorder. Crystal Structure Refinement A Crystallographer’s Guide to SHELXL; Oxford University Press, 2006; pp 56–59. [Google Scholar]
  67. Accelrys, Materials Studio Getting Started, release 7.0; Accelrys Software, Inc., San Diego, CA, 2014.

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

tz3c01157_si_001.pdf (4.6MB, pdf)
tz3c01157_si_002.zip (8.9MB, zip)
tz3c01157_si_003.cif (841.7KB, cif)
tz3c01157_si_004.cif (1.8MB, cif)
tz3c01157_si_005.cif (684.2KB, cif)
tz3c01157_si_006.cif (1.4MB, cif)
tz3c01157_si_007.cif (1.8MB, cif)

Articles from ACS Materials Letters are provided here courtesy of American Chemical Society

RESOURCES