Highly Selective Separation of C2H2/CO2 and C2H2/C2H4 in an N-Rich Cage-Based Microporous Metal-Organic Framework

Yang, Lingzhi; Xie, Wenpeng; Fu, Qiuju; Yan, Liting; Zhang, Shuo; Jiang, Huimin; Li, Liangjun; Gu, Xin; Liu, Dandan; Dai, Pengcheng; Zheng, Qingbin; Zhao, Xuebo

doi:https://doi.org/10.1155/2023/4740672

Adsorption Science & Technology

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Abstract Introduction Materials and Methods Results and Discussion Conclusions Data Availability Conflicts of Interest Acknowledgments Supplementary Materials References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 4740672 | https://doi.org/10.1155/2023/4740672

Highly Selective Separation of C₂H₂/CO₂ and C₂H₂/C₂H₄ in an N-Rich Cage-Based Microporous Metal-Organic Framework

Lingzhi Yang,^1,2Wenpeng Xie,³Qiuju Fu,³Liting Yan,¹Shuo Zhang,^1,3Huimin Jiang,^1,3Liangjun Li,³Xin Gu,³Dandan Liu,³Pengcheng Dai,³Qingbin Zheng,²and Xuebo Zhao¹

Academic Editor: Adrián Bonilla-Petriciolet

Received16 Dec 2022

Revised21 Jan 2023

Accepted09 Feb 2023

Published01 Mar 2023

Abstract

The separation of acetylene (C₂H₂) from carbon dioxide (CO₂) and the purification of ethylene (C₂H₄) from C₂H₂ are quite essential processes for the chemical industry. However, these processes are challenging due to their similar physical properties, including molecule sizes and boiling points. Herein, we report an N-rich cage-based microporous metal-organic framework (MOF), [Cd₅(Tz)₉](NO₃) (termed as Cd-TZ, TZ stands for tetrazole), and its highly efficient separation of C₂H₂/CO₂ and C₂H₂/C₂H₄. Single-component gas adsorption isotherms reveal that Cd-TZ exhibits high C₂H₂ adsorption capacity (3.10 mmol g^-1 at 298 K and 1 bar). The N-rich cages in Cd-TZ can trap C₂H₂ with a higher isosteric heat of adsorption (40.8 kJ mol^-1) than CO₂ and C₂H₄ owing to the robust host-guest interactions between the noncoordinated N atoms and C₂H₂, which has been verified by molecular modeling studies. Cd-TZ shows a high IAST selectivity for C₂H₂/CO₂ (8.3) and C₂H₂/C₂H₄ (13.3). The breakthrough simulations confirm the potential for separating C₂H₂/CO₂ and the purification of C₂H₄ from C₂H₂.

1. Introduction

C₂H₂ and C₂H₄ are two of the most important chemical raw feedstocks for producing various commercial chemicals [1]. C₂H₂ is mainly obtained from coal or coal-derived coke with direct or indirect processes [2]. Thus, CO₂ is usually contained in the crude acetylene as an unavoidable impurity generally removed in an aqueous sodium hydroxide wash. C₂H₂ can also be purified by dissolving in organic solvents, such as N-methylpyrrolidone and dimethylformamide. C₂H₄ is typically produced by the pyrolysis of ethane gas or light naphtha, with a small amount of C₂H₂ generated. C₂H₂ in mixtures must be removed, reducing its content to below 5 ppm [3, 4] because of the effects of C₂H₂ in poisoning catalysis during the polymerization process of ethylene. Solvent extraction and partial hydrogenation are the main commercial techniques to separate trace C₂H₂ from C₂H₄. However, both the purification methods of C₂H₂ and C₂H₄ used in the chemical industry are with poor separation selectivity and are energy-intensive [5]. Alternatively, selective adsorption and separation processes based on porous sorbents are energy-efficient and sustainable.

In recent decades, MOFs [6–12] have been studied widely in separations and purifications for hydrocarbons [13–24]. However, the molecular sizes ( for C₂H₂, for CO₂, and for C₂H₄) and kinetic diameter (3.3 Å for C₂H₂, 3.3 Å for CO₂, and 4.2 Å for C₂H₄) of acetylene, carbon dioxide, and ethylene are very close [7, 25], making the efficient separation of C₂H₂/CO₂ and C₂H₂/C₂H₄ a challenge. Until now, MOFs [7, 26–31] with highly selective separation performance for both C₂H₂/CO₂ and C₂H₂/C₂H₄ are still rare. Currently, the reported MOF materials with record selectivity for C₂H₂/CO₂ and C₂H₂/C₂H₄ is an anion-pillared flexible MOF, UTSA-300a [26]. Because of the strong C–H···F hydrogen-bonding interaction between UTSA-300a and C₂H₂, C₂H₂ can easily open the pore and be adsorbed into it while the other gases are blocked out of the pore. Lee and co-workers [28] reported a cationic MOF, JCM-1, which possesses imidazolium and nitrate groups in the pore channel, exhibiting a higher selectivity and adsorption affinity for C₂H₂ than for CO₂ or C₂H₄. A broad strategy in MOFs to enhance the selectivity of C₂H₂/CO₂ and C₂H₂/C₂H₄ is to increase the polar groups or adsorption sites, such as fluorine/nitrogen/oxygen-containing functional groups, to strengthen the interaction with C₂H₂ over CO₂ or C₂H₄.

Herein, we report a microporous MOF [Cd₅(Tz)₉](NO₃) [32] with N-rich cavities for the preferential adsorption of C₂H₂ and the efficient separation for C₂H₂/CO₂ and C₂H₂/C₂H₄. At ambient conditions, Cd-TZ shows a higher adsorption capacity and isosteric heat of adsorption for C₂H₂ than for CO₂ and C₂H₄. Thus, Cd-TZ exhibits elevated C₂H₂/CO₂ and C₂H₂/C₂H₄ selectivity. The modeling studies reveal that the trapped C₂H₂ molecule is in the center of the cavity and strongly interacts with the surrounding N atoms. The simulated breakthrough curves demonstrate the effective separation of binary mixtures of C₂H₂/CO₂ and C₂H₂/C₂H₄.

2. Materials and Methods

2.1. Materials

All reagents and solvents were commercially available and, unless otherwise noted, were used without further purification. Cadmium nitrate tetrahydrate (Cd(NO₃)₂·4H₂O, AR) was purchased from Aladdin Reagent Co. Ltd. Ethyl tetrazole-5-carboxylate (>95%) was purchased from Bidepharm Co. Ltd.

High-purity CO₂ (99.999%), C₂H₄ (99.95%), and C₂H₂ (99.9%) were purchased from Qingdao Tianyuan Gas Co., Ltd. C₂H₂ was filtered through activated carbon to remove traces of acetone before use.

2.2. Synthesis of Cd-TZ

Cd-TZ was synthesized according to the methods reported in the literature [32]. A mixture of Cd(NO₃)₂·4H₂O and ethyl tetrazole-5-carboxylate was dissolved in 10 mL H₂O, then transferred to a 23 mL Teflon-lined autoclave and heated at 433 K for 72 h, followed by cooling to room temperature. Colorless crystals were collected by filtration and washed with H₂O and methanol. The activation process of the Cd-TZ sample was conducted under a vacuum at 423 K for 12 h.

2.3. Characterizations of Cd-TZ

Thermogravimetric analyses (TGA) were examined using a Netzsch STA 449C instrument under an N₂ atmosphere with a heating rate of 5 K min^-1. Powder X-ray diffraction (PXRD) data were performed on an X-ray diffractometer (Bruker D8 Adv., Germany) with Cu Kα radiation from 5 to 50° () and a step size of 0.0167° in 2θ.

2.4. Adsorption Studies for CO₂, C₂H₂, and C₂H₄

The sample was degassed in a vacuum for 12 h at 423 K to remove guest molecules before adsorption. Equilibrium and kinetic adsorption experiments of CO₂, C₂H₂, and C₂H₄ were measured using a XEMIS magnetic suspension balance sorption analyzer (Hiden, UK) equipped with a circulating water bath at 273 K and 298 K, respectively.

2.5. Calculation of Brunauer-Emmett-Teller (BET) Surface Area and Langmuir Surface Area

Surface areas of Cd-TZ were calculated using the BET equation and Langmuir equation based on the CO₂ adsorption isotherm at 273 K.

BET surface area:

Langmuir surface area: where is the pressure (bar), is the saturated vapor pressure, is the adsorption amount under the corresponding pressure, is the amount related to the monolayer surface coverage, () and are constants, is the cross-sectional area of CO₂ (), and and are the calculated BET surface area and Langmuir surface area, respectively.

2.6. Calculation of Isosteric Enthalpy of Adsorption

Isosteric enthalpy of adsorption () was calculated from isotherms measured at 273 K and 298 K for CO₂, C₂H₂, and C₂H₄. The isotherms were firstly fit to a virial equation: where is the pressure expressed in mbar, is the amount adsorbed in mmol g^-1, is the temperature in K, and are virial coefficients, and and represent the number of coefficients required to describe the isotherms adequately. To calculate , the fitting parameters from the above equation were used for the following equation:

2.7. Ideal Adsorbed Solution Theory (IAST) Selectivity Calculation

The gas adsorption isotherms were firstly fitted to a dual-site Langmuir-Freundlich (DSLF) equation: where (mmol g^-1) is the amount of adsorbed gas; (mbar) is the bulk gas phase pressure; (mmol g^-1) and (mmol g^-1) are the saturation capacities of sites 1 and 2, respectively; (mbar^-n1) and (mbar^-n2) are the affinity coefficients of site 1 and site 2, respectively; and and represent the deviations from an ideal homogeneous surface.

The adsorption selectivity is defined by where and are the mole fractions of component ( and 2) in the adsorbed and bulk phases, respectively.

2.8. Density-Functional Theory Calculations

All the geometry optimizations and binding energies were calculated by the periodic density functional theory (DFT) method using the DMol³ module. The host framework and the gas molecule were both regarded as rigid. The structures of the framework were first optimized. Then, guest gas molecules were introduced to the optimized framework, followed by a full structure relaxation. An isolated gas molecule placed in a supercell (with the same cell dimensions as the framework) was also relaxed as a reference to obtain the gas binding energy. The widely used generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional and the double numerical plus polarization (DNP) basis set, the Grimme method for DFT-D correction, and the DFT semicore pseudopots (DSPP) were used. The energy, force, and displacement convergence criteria were set as , , and , respectively. The following equations then calculated the static binding energy (at ): where is the static binding energy between the MOF and the gas molecule and , , and are the energies of the gas-free MOF, the free gas molecule, and the MOF-gas system, respectively.

2.9. Breakthrough Simulation

Breakthrough simulations were performed using the 3P-Sim software. In the simulated separation experiment, the Cd-TZ (1.0 g) was packed into the column with a length of 5 cm and an inner diameter of 0.45 cm. And the simulated operating condition is under 1 bar at 298 K with a continuous gas (C₂H₂/CO₂ (50/50, ) or C₂H₂/C₂H₄ (50/50, )) flow of 2 mL (STP) min^-1.

3. Results and Discussion

As shown in Figures 1(a) and 1(b), each Cd (II) atom in the framework is surrounded by different tetrazole ligands and coordinated with six nitrogen atoms to form an octahedral coordination structure, resulting in a cationic three-dimensional framework [Cd₅(Tz)₉]⁺ which is balanced by NO₃^-. Cd (II) atoms interconnect such six second-building units to form one-dimensional straight pore channels (4.6 Å), which have large cavities (5.3 Å) parallel to each other along the axis (Figures 1(c) and 1(d)). The surface of the cavities contains many uncoordinated tetrazole nitrogen atoms, which is conducive to capturing C₂H₂ molecules. Cd-TZ was successfully prepared by hydrothermal reaction at 433 K, and the phase purity of the material was identified by PXRD patterns which nicely match the calculated patterns from single crystal data (Figure 2(a)). To investigate the thermal stability of Cd-TZ, the synthesized Cd-TZ samples were subjected to TGA under a nitrogen atmosphere, as shown in Figure 2(b). The TGA curves show that the Cd-TZ sample lost most of the free water molecules in the pore channels as the temperature increased to 98°C. When the temperature exceeded 300°C, the sample lost weight rapidly. This phenomenon indicates that Cd-TZ has good thermal stability under a nitrogen atmosphere and can maintain the structure over a wide temperature range (<300°C). The specific surface area of Cd-TZ was characterized using CO₂ adsorption experiments performed at 273 K (Figure S1a). And the BET surface area (Figure S1b) and Langmuir surface area (Figure S2) were calculated to be 388 m² g^-1 and 403 m² g^-1, respectively.

(a)

(b)

(c)

(d)

(a)

(b)

Considering the suitable pore size and the presence of abundant uncoordinated nitrogen atoms in the pore surface of Cd-TZ, we were intrigued to explore its potential to capture C₂H₂ and, further, to separate C₂H₂/CO₂ and C₂H₂/C₂H₄. Therefore, single-component adsorption-desorption isotherms of C₂H₂, CO₂, and C₂H₄ were collected at 273 K and 298 K (Figures 3(a) and 3(b)). The adsorption capacity of C₂H₂ is higher than those of CO₂ and C₂H₄ in Cd-TZ under the same conditions. The C₂H₂ capacity is 3.10 mmol g^-1 at 298 K and 1 bar, higher than the capacity of CO₂ (2.07 mmol g^-1) and C₂H₄ (1.68 mmol g^-1) and outperforming many reported MOFs, such as ZU-62-Ni (3.0 mmol g^-1) [33], NKMOF-1-Ni (2.7 mmol g^-1) [34], Zn(ad)(int) (2.32 mmol g^-1) [35], CPL-1-NH₂ (1.84 mmol g^-1) [36], and Zn-FBA (1.03 mmol g^-1) [37]. Furthermore, the C₂H₂ adsorption isotherms rise rapidly in the low-pressure region at 273 K and 298 K. At 298 K and 0.01 bar, the uptake ratio of C₂H₂/CO₂ and C₂H₂/C₂H₄ in Cd-TZ is 1.8 and 3.0, respectively, indicating the stronger interaction between C₂H₂ and Cd-TZ. The isosteric enthalpies of adsorption for C₂H₂, CO₂, and C₂H₄ were calculated based on fitting using the virial method (Figure S3-S5) to evaluate the interaction between the framework and the guest molecule. As shown in Figure 3(c), the calculated value of for C₂H₂, CO₂, and C₂H₄ at zero loading is 40.8 kJ mol^-1, 35.6 kJ mol^-1, and 31.8 kJ mol^-1, respectively. Furthermore, the value of Cd-TZ for C₂H₂ is higher than those for CO₂ and C₂H₄ over the entire pressure range from 0 to 1 bar. All the results demonstrate that Cd-TZ prefers to adsorb C₂H₂ and has a stronger affinity for C₂H₂ than CO₂ and C₂H₄, which prompts us to explore the separation performance of Cd-TZ for the binary gas of C₂H₂/CO₂ and C₂H₂/C₂H₄.

(a)

(b)

(c)

The adsorption selectivity for C₂H₂/CO₂ (50/50, ) and C₂H₂/C₂H₄ (50/50, 1/99, ) was calculated based on the IAST model based on fitting using the DSLF equation (Figure S6-S8). The selectivity of Cd-TZ for C₂H₂/CO₂ (50/50, ) is 8.3 at 298 K and 1.0 bar (Figure S9), which is compared to the reported UTSA-74a (9.0) [38], and superior to some of the benchmark MOFs like SIFSIX-21-Ni (7.8) [39], TIFSIX-2-Cu-i (6.5) [40], FJU-90a (4.3) [41], and ZrT-1-tetrazl (2.8) [42] under similar conditions. As shown in Figure S10, the selectivity of Cd-TZ for the binary mixtures of C₂H₂/C₂H₄ (50/50, ) is up to 20.1 at 273 K and 1 bar, with the temperature increasing to 298 K, and the selectivity is about 13.3, which surpasses most of the reported MOFs, such as cPAF-28 (12.2) [43], MUF-17 (8.73) [30], NbU-1 (5.9) [44], CuTiF₆-TPPY (5.47) [45], and Fe-MOF-74 (2.1) [46]. Consider that C₂H₂ is a minor impurity in the crude C₂H₄ production by the cracking of ethane. Therefore, the IAST selectivity of C₂H₂/C₂H₄ (1/99, ) was also calculated in addition to that of C₂H₂/C₂H₄ (50/50, ). The calculated IAST selectivity value for the binary mixtures of C₂H₂/C₂H₄ (1/99, ) is 7.3 higher than those of SIFSIX-3-Ni (5.0) [47] and NUM-11a (1.65) [48]. These calculation results further indicate that Cd-TZ is a potential porous material in separating C₂H₂/CO₂ and removing C₂H₂ from C₂H₄.

The optimal adsorption sites of C₂H₂, C₂H₄, and CO₂ in the framework of Cd-TZ were elucidated by DFT calculations. The calculated static binding energy of C₂H₂ in Cd-TZ is 75.1 kJ mol^-1, much higher than those of C₂H₄ with 54.4 kJ mol^-1 and CO₂ with 35.6 kJ mol^-1. The lowest-energy binding configuration of C₂H₂, C₂H₄, and CO₂ in Cd-TZ is shown in Figure 4, indicating that the adsorbed C₂H₂ molecule is trapped in the center of the cavity and strongly interacts with the surrounding N atoms, which are highly electronegative. Figure S11 shows that the optimized distance between one H atom of C₂H₂ and the noncoordinated N atom in the cavity is 2.14 Å, which is smaller than the sum of the van der Waals radius of the H atom (1.20 Å) and N atom (1.55 Å). Moreover, the calculated distances between C atoms of C₂H₂ and H atoms of tetrazole are 2.72 Å and 2.74 Å, respectively, shorter than the sum of the van der Waals radius of H and C atoms, 2.90 Å. These results indicate the robust affinity of the framework to the C₂H₂ molecules. C₂H₄ has a larger size and planar configuration. Thus, only one end of the =CH₂ group is adsorbed in the cavity with side-on orientation and forms a weaker interaction with the surrounding tetrazoles (Figure S12). There are four C=C-H···N dipolar interactions (2.89 Å, 2.92 Å, 3.10 Å, and 3.10 Å) observed between C₂H₄ and the tetrazoles in the cavity. And the calculated H-C=C···H distances between C₂H₄ and the tetrazoles in the cavity are 2.70~2.89 Å (2.70 Å, 2.73 Å, 2.87 Å, and 2.89 Å). As shown in Figure S13, CO₂ has two weak C_CO2···N interactions and three weak O_CO2···H interactions with the tetrazoles. The calculated distance of C_CO2···N is 3.40 Å and 3.47 Å, while the estimated distance of O_CO2···H is 2.85 Å, 3.41 Å, and 3.49 Å, indicating the weak interaction between CO₂ and the framework. The simulation calculations confirm that the adsorption affinity of C₂H₂ is much stronger than C₂H₄ and CO₂, consistent with the experimental results.

(a)

(b)

(c)

The separation performance of Cd-TZ was investigated by breakthrough simulations with the binary gas mixture of C₂H₂/CO₂ (50/50, ) and C₂H₂/C₂H₄ (50/50, ) at 298 K and 1 bar. As shown in Figure 5(a), CO₂ gas was first eluted at 31 min from the column, whereas C₂H₂ was retained in the column until 50 min, demonstrating a stronger binding affinity of the framework to C₂H₂ molecules. Figure 5(b) shows that Cd-TZ can realize the complete separation of C₂H₂/C₂H₄ (50/50, ). The C₂H₄ broke through from the column after 30 minutes, and no C₂H₂ was eluted out before 53 minutes, indicating that high-purity C₂H₄ could be obtained with the framework. All the above results demonstrate the great potential of Cd-TZ in the separation of C₂H₂/CO₂ and C₂H₂/C₂H₄ in practice.

(a)

(b)

4. Conclusions

In summary, we have investigated the N-rich cage-based microporous metal-organic framework, Cd-TZ, showing a stronger affinity for C₂H₂ than CO₂ and C₂H₄, and efficiently separating binary mixtures of C₂H₂/CO₂ and C₂H₂/C₂H₄. Owing to the abundant uncoordinated nitrogen atoms on the pore surface and the cavities, Cd-TZ exhibits a high capacity for C₂H₂ (3.10 mmol g^-1 at 298 K and 1 bar). The calculated IAST selectivity of Cd-TZ for C₂H₂/CO₂ and C₂H₂/C₂H₄ is 8.3 and 13.3, respectively. The breakthrough simulation results well confirm the separation performance of Cd-TZ. In addition, the preferential binding of C₂H₂ over CO₂ and C₂H₄ is clearly demonstrated by DFT calculations. This study provides an exquisite example of MOF possessing abundant electronegative nitrogen sites on the pore surfaces and the cavities for the challenging separation of C₂H₂/CO₂ and C₂H₂/C₂H₄.

Data Availability

The data used to support the findings of this study are available from the corresponding authors upon request. In addition, all of the experimental datasets are available from the online Zenodo repository (10.5281/zenodo.7645931) [49].

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

This work was financially supported by the University Development Fund (UDF0100152), the National Natural Science Foundation of China (21975286, 22205189), the Qilu University of Technology Special Funding for Distinguished Scholars (Grant No. 2419010420), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (Grant No. 2017ZT07C291), and the China Postdoctoral Science Foundation (Grant No. 2022M723030).

Supplementary Materials

Figure S1-S2: the specific surface area calculations of Cd-TZ. Figure S3-S5: C₂H₂, C₂H₄, and CO₂ isotherm fittings using the virial method. Figure S6-S8: C₂H₂, C₂H₄, and CO₂ isotherm fittings using the DSLF equation. Figure S9-S10: IAST adsorption selectivity for C₂H₂/CO₂ and C₂H₂/C₂H₄. Figure S11-S13: the optimal adsorption sites of C₂H₂, C₂H₄, and CO₂ in Cd-TZ. (Supplementary Materials)

References

S. Mukherjee, D. Sensharma, K.-J. Chen, and M. J. Zaworotko, “Crystal engineering of porous coordination networks to enable separation of C₂ hydrocarbons,” Chemical Communications, vol. 56, no. 72, pp. 10419–10441, 2020.
View at: Publisher Site | Google Scholar
H. Schobert, “Production of acetylene and acetylene-based chemicals from coal,” Chemical Reviews, vol. 114, no. 3, pp. 1743–1760, 2014.
View at: Publisher Site | Google Scholar
Y. Chai, X. Han, W. Li et al., “Control of zeolite pore interior for chemoselective alkyne/olefin separations,” Science, vol. 368, no. 6494, pp. 1002–1006, 2020.
View at: Publisher Site | Google Scholar
H. Zimmermann and R. Walzl, “Ethylene,” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH Publishing, 2009.
View at: Publisher Site | Google Scholar
T. Ren, M. Patel, and K. Blok, “Olefins from conventional and heavy feedstocks: energy use in steam cracking and alternative processes,” Energy, vol. 31, no. 4, pp. 425–451, 2006.
View at: Publisher Site | Google Scholar
S. Kitagawa, R. Kitaura, and S. Noro, “Functional porous coordination polymers,” Angewandte Chemie International Edition, vol. 43, no. 18, pp. 2334–2375, 2004.
View at: Publisher Site | Google Scholar
B.-Y. Zhu, T. Zhang, C.-H. Li et al., “A (3,8)-connected metal-organic framework with bending dicarboxylate linkers for C₂H₂/CO₂ separation,” Inorganic Chemistry, vol. 61, no. 11, pp. 4555–4560, 2022.
View at: Publisher Site | Google Scholar
Y. Deng, Q. Mao, S. Luo, X. Xie, and L. Luo, “Adsorption-based removal of Sb (III) from wastewater by graphene oxide-modified zirconium-based metal-organic framework composites,” Adsorption Science & Technology, vol. 2022, article 9222441, pp. 1–13, 2022.
View at: Publisher Site | Google Scholar
K. Wang, Y. Li, L.-H. Xie, X. Li, and J.-R. Li, “Construction and application of base-stable MOFs: a critical review,” Chemical Society Reviews, vol. 51, no. 15, pp. 6417–6441, 2022.
View at: Publisher Site | Google Scholar
F. G. Quintero-Alvarez, C. K. Rojas-Mayorga, D. I. Mendoza-Castillo, I. A. Aguayo-Villarreal, and A. Bonilla-Petriciolet, “Physicochemical modeling of the adsorption of pharmaceuticals on MIL-100-Fe and MIL-101-Fe MOFs,” Adsorption Science & Technology, vol. 2022, article 4482263, pp. 1–14, 2022.
View at: Publisher Site | Google Scholar
J.-W. Wang, S.-C. Fan, H.-P. Li, X. Bu, Y.-Y. Xue, and Q.-G. Zhai, “De-linker-enabled exceptional volumetric acetylene storage capacity and benchmark C₂H₂/C₂H₄ and C₂H₂/CO₂ separations in metal–organic frameworks,” Angewandte Chemie International Edition, vol. 62, no. 10, 2023.
View at: Publisher Site | Google Scholar
Z. Zhang, P. Li, T. Zhao, and Y. Xia, “Enhanced CO₂ adsorption and selectivity of CO₂/N₂ on amine@ZIF-8 materials,” Adsorption Science & Technology, vol. 2022, article 3207986, pp. 1–12, 2022.
View at: Publisher Site | Google Scholar
J.-R. Li, R. J. Kuppler, and H.-C. Zhou, “Selective gas adsorption and separation in metal-organic frameworks,” Chemical Society Reviews, vol. 38, no. 5, pp. 1477–1504, 2009.
View at: Publisher Site | Google Scholar
J.-R. Li, J. Sculley, and H.-C. Zhou, “Metal-organic frameworks for separations,” Chemical Reviews, vol. 112, no. 2, pp. 869–932, 2012.
View at: Publisher Site | Google Scholar
R.-B. Lin, L. Li, H.-L. Zhou et al., “Molecular sieving of ethylene from ethane using a rigid metal-organic framework,” Nature Materials, vol. 17, no. 12, pp. 1128–1133, 2018.
View at: Publisher Site | Google Scholar
H. Li, L. Li, R.-B. Lin et al., “Porous metal-organic frameworks for gas storage and separation: status and challenges,” EnergyChem, vol. 1, no. 1, article 100006, 2019.
View at: Publisher Site | Google Scholar
K.-J. Chen, D. G. Madden, S. Mukherjee et al., “Synergistic sorbent separation for one-step ethylene purification from a four-component mixture,” Science, vol. 366, no. 6462, pp. 241–246, 2019.
View at: Publisher Site | Google Scholar
Q. Dong, X. Zhang, S. Liu et al., “Tuning gate-opening of a flexible metal–organic framework for ternary gas sieving separation,” Angewandte Chemie International Edition, vol. 59, no. 50, pp. 22756–22762, 2020.
View at: Publisher Site | Google Scholar
Z. Xu, X. Xiong, J. Xiong et al., “A robust Th-azole framework for highly efficient purification of C₂H₄ from a C₂H₄/C₂H₂/C₂H₆ mixture,” Nature Communications, vol. 11, no. 1, p. 3163, 2020.
View at: Publisher Site | Google Scholar
X. Zhang, J.-X. Wang, L. Li et al., “A rod-packing hydrogen-bonded organic framework with suitable pore confinement for benchmark ethane/ethylene separation,” Angewandte Chemie International Edition, vol. 60, no. 18, pp. 10304–10310, 2021.
View at: Publisher Site | Google Scholar
Y. Yang, L. Li, R.-B. Lin et al., “Ethylene/ethane separation in a stable hydrogen-bonded organic framework through a gating mechanism,” Nature Chemistry, vol. 13, no. 10, pp. 933–939, 2021.
View at: Publisher Site | Google Scholar
Y. Wang, C. Hao, W. Fan et al., “One-step ethylene purification from an acetylene/ethylene/ethane ternary mixture by cyclopentadiene cobalt-functionalized metal–organic frameworks,” Angewandte Chemie International Edition, vol. 60, no. 20, pp. 11350–11358, 2021.
View at: Publisher Site | Google Scholar
J.-W. Cao, S. Mukherjee, T. Pham et al., “One-step ethylene production from a four-component gas mixture by a single physisorbent,” Nature Communications, vol. 12, no. 1, p. 6507, 2021.
View at: Publisher Site | Google Scholar
T. Zhang, J.-W. Cao, S.-Y. Zhang et al., “General pore features for one-step C₂H₄ production from a C₂ hydrocarbon mixture,” Chemical Communications, vol. 58, no. 32, pp. 4954–4957, 2022.
View at: Publisher Site | Google Scholar
C. E. Webster, R. S. Drago, and M. C. Zerner, “Molecular dimensions for adsorptives,” Journal of the American Chemical Society, vol. 120, no. 22, pp. 5509–5516, 1998.
View at: Publisher Site | Google Scholar
R.-B. Lin, L. Li, H. Wu et al., “Optimized separation of acetylene from carbon dioxide and ethylene in a microporous material,” Journal of the American Chemical Society, vol. 139, no. 23, pp. 8022–8028, 2017.
View at: Publisher Site | Google Scholar
M. Jiang, X. Cui, L. Yang et al., “A thermostable anion-pillared metal-organic framework for C₂H₂/C₂H₄ and C₂H₂/CO₂ separations,” Chemical Engineering Journal, vol. 352, pp. 803–810, 2018.
View at: Publisher Site | Google Scholar
J. Lee, C. Y. Chuah, J. Kim et al., “Separation of acetylene from carbon dioxide and ethylene by a water-stable microporous metal–organic framework with aligned imidazolium groups inside the channels,” Angewandte Chemie International Edition, vol. 57, no. 26, pp. 7869–7873, 2018.
View at: Publisher Site | Google Scholar
L.-N. Ma, Z.-H. Wang, L. Zhang, L. Hou, Y.-Y. Wang, and Z. Zhu, “Extraordinary Separation of Acetylene-Containing Mixtures in a Honeycomb Calcium-Based MOF with Multiple Active Sites,” ACS Applied Materials & Interfaces, vol. 15, no. 2, pp. 2971–2978, 2023.
View at: Publisher Site | Google Scholar
O. T. Qazvini, R. Babarao, and S. G. Telfer, “Multipurpose metal-organic framework for the adsorption of acetylene: ethylene purification and carbon dioxide removal,” Chemistry of Materials, vol. 31, no. 13, pp. 4919–4926, 2019.
View at: Publisher Site | Google Scholar
Y. Du, Y. Chen, Y. Wang et al., “Optimized pore environment for efficient high selective C₂H₂/C₂H₄ and C₂H₂/CO₂ separation in a metal-organic framework,” Separation and Purification Technology, vol. 256, article 117749, 2021.
View at: Publisher Site | Google Scholar
D.-C. Zhong, J.-B. Lin, W.-G. Lu, L. Jiang, and T.-B. Lu, “Strong hydrogen binding within a 3D microporous metal-organic framework,” Inorganic Chemistry, vol. 48, no. 18, pp. 8656–8658, 2009.
View at: Publisher Site | Google Scholar
L. Yang, A. Jie, L. Ge, X. Cui, and H. Xing, “A novel interpenetrated anion-pillared porous material with high water tolerance afforded efficient C₂H₂/C₂H₄ separation,” Chemical Communications, vol. 55, no. 34, pp. 5001–5004, 2019.
View at: Publisher Site | Google Scholar
Y.-L. Peng, T. Pham, P. Li et al., “Robust ultramicroporous metal–organic frameworks with benchmark affinity for acetylene,” Angewandte Chemie International Edition, vol. 57, no. 34, pp. 10971–10975, 2018.
View at: Publisher Site | Google Scholar
Q. Ding, Z. Zhang, Y. Liu, K. Chai, R. Krishna, and S. Zhang, “One-step ethylene purification from ternary mixtures in a metal–organic framework with customized pore chemistry and shape,” Angewandte Chemie International Edition, vol. 61, no. 35, article e202208134, 2022.
View at: Google Scholar
L. Yang, L. Yan, Y. Wang et al., “Adsorption site selective occupation strategy within a metal–organic framework for highly efficient sieving acetylene from carbon dioxide,” Angewandte Chemie International Edition, vol. 60, no. 9, pp. 4570–4574, 2021.
View at: Publisher Site | Google Scholar
L. Yang, L. Yan, W. Niu et al., “Adsorption in reversed order of C₂ hydrocarbons on an ultramicroporous fluorinated metal-organic framework,” Angewandte Chemie International Edition, vol. 61, no. 25, article e202204046, 2022.
View at: Google Scholar
F. Luo, C. Yan, L. Dang et al., “UTSA-74: a MOF-74 isomer with two accessible binding sites per metal center for highly selective gas separation,” Journal of the American Chemical Society, vol. 138, no. 17, pp. 5678–5684, 2016.
View at: Publisher Site | Google Scholar
N. Kumar, S. Mukherjee, N. C. Harvey-Reid et al., “Breaking the trade-off between selectivity and adsorption capacity for gas separation,” Chem, vol. 7, no. 11, pp. 3085–3098, 2021.
View at: Publisher Site | Google Scholar
K.-J. Chen, H. S. Scott, D. G. Madden et al., “Benchmark C₂H₂/CO₂ and CO₂/C₂H₂ separation by two closely related hybrid ultramicroporous materials,” Chem, vol. 1, no. 5, pp. 753–765, 2016.
View at: Publisher Site | Google Scholar
Y. Ye, Z. Ma, R.-B. Lin et al., “Pore space partition within a metal-organic framework for highly efficient C₂H₂/CO₂ separation,” Journal of the American Chemical Society, vol. 141, no. 9, pp. 4130–4136, 2019.
View at: Publisher Site | Google Scholar
W. Fan, S. B. Peh, Z. Zhang et al., “Tetrazole-functionalized zirconium metal-organic cages for efficient C₂H₂/C₂H₄ and C₂H₂/CO₂ separations,” Angewandte Chemie International Edition, vol. 60, no. 32, pp. 17338–17343, 2021.
View at: Publisher Site | Google Scholar
S. Zhou, Z. Liu, P. Zhang et al., “Tailoring the pore chemistry in porous aromatic frameworks for selective separation of acetylene from ethylene,” Chemical Science, vol. 13, no. 37, pp. 11126–11131, 2022.
View at: Publisher Site | Google Scholar
J. Li, L. Jiang, S. Chen et al., “Metal-organic framework containing planar metal-binding sites: efficiently and cost-effectively enhancing the kinetic separation of C₂H₂/C₂H₄,” Journal of the American Chemical Society, vol. 141, no. 9, pp. 3807–3811, 2019.
View at: Publisher Site | Google Scholar
P. Zhang, Y. Zhong, Y. Zhang et al., “Synergistic binding sites in a hybrid ultramicroporous material for one-step ethylene purification from ternary C₂ hydrocarbon mixtures,” Science Advances, vol. 8, no. 23, 2022.
View at: Google Scholar
E. D. Bloch, W. L. Queen, R. Krishna, J. M. Zadrozny, C. M. Brown, and J. R. Long, “Hydrocarbon separations in a metal-organic framework with open iron(II) coordination sites,” Science, vol. 335, no. 6076, pp. 1606–1610, 2012.
View at: Publisher Site | Google Scholar
X. Cui, K. Chen, H. Xing et al., “Pore chemistry and size control in hybrid porous materials for acetylene capture from ethylene,” Science, vol. 353, no. 6295, pp. 141–144, 2016.
View at: Publisher Site | Google Scholar
S.-Q. Yang, L. Zhou, Y. He et al., “Two-dimensional metal-organic framework with ultrahigh water stability for separation of acetylene from carbon dioxide and ethylene,” ACS Applied Materials & Interfaces, vol. 14, no. 29, pp. 33429–33437, 2022.
View at: Publisher Site | Google Scholar
L. Yang and X. Zhao, Highly Selective Separation of C₂H₂/CO₂ and C₂H₂/C₂H₄ in an N-Rich Cage-Based Microporous Metal-Organic Framework, Zenodo, 2023.
View at: Publisher Site

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Copyright © 2023 Lingzhi Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Adsorption Science & Technology

Highly Selective Separation of C2H2/CO2 and C2H2/C2H4 in an N-Rich Cage-Based Microporous Metal-Organic Framework

Abstract

1. Introduction

2. Materials and Methods

2.1. Materials

2.2. Synthesis of Cd-TZ

2.3. Characterizations of Cd-TZ

2.4. Adsorption Studies for CO2, C2H2, and C2H4

2.5. Calculation of Brunauer-Emmett-Teller (BET) Surface Area and Langmuir Surface Area

2.6. Calculation of Isosteric Enthalpy of Adsorption

2.7. Ideal Adsorbed Solution Theory (IAST) Selectivity Calculation

2.8. Density-Functional Theory Calculations

2.9. Breakthrough Simulation

3. Results and Discussion

4. Conclusions

Data Availability

Conflicts of Interest

Acknowledgments

Supplementary Materials

References

Copyright

Highly Selective Separation of C₂H₂/CO₂ and C₂H₂/C₂H₄ in an N-Rich Cage-Based Microporous Metal-Organic Framework

2.4. Adsorption Studies for CO₂, C₂H₂, and C₂H₄