High Performance CO2 Separation Research Articles

Manipulating the monomers supply of interfacial polymerization towards the ultrathin polyamide composite membrane for CO2 capture

Manipulating the monomers supply of interfacial polymerization towards the ultrathin polyamide composite membrane for CO2 capture

Large-scale preparation of composite membranes for CO2 separation via interfacial polymerization: Monomer selection and processing parameter optimization

Large-scale preparation of composite membranes for CO2 separation via interfacial polymerization: Monomer selection and processing parameter optimization

In-house synthesized poly(ether ether ketone) ionenes. I. ToF-SIMS spectra in the positive ion mode

Static time-of-flight secondary ion mass spectrometry (ToF-SIMS) was performed for acquiring the high-resolution surface spectra of four types of synthesized imidazolium ionene membranes. These novel membranes have aromatic ether–ketone–ether linkages inspired by poly(ether ether ketone) (PEEK). The PEEK-ionenes synthesized for this study have imidazolium cations placed in the polymeric backbone with bistriflimide [Tf2N]− counterions. The attention given to synthetically modified PEEK derivatives, such as PEEK-ionenes, is considerable due to their ability to selectively capture CO2 molecules and other light gases. Therefore, it is important to characterize the surface of these synthesized novel PEEK-ionenes. In this work, characteristic and unique peaks were identified in the positive spectra of each sample. The differences in mass spectra among the samples provide insights for optimizing or fine-tuning the PEEK-ionenes synthesis to achieve a high-performance CO2 separation membrane with enhanced permeability, selectivity, and mechanical stability. The SIMS spectra and identified characteristic peaks of these synthesized ionenes will serve as a reference in the positive mode, complementing the corresponding spectra reported in the negative ion mode (Paper II).

Three Robust Isoreticular Metal-Organic Frameworks with High-Performance Selective CO2 Capture and Separation.

Based on the hard-soft acid base (HSAB) theory, three robust isoreticular metal-organic frameworks (MOFs) with nia topology were successfully synthesized by solvothermal reaction {[In3O(BHB)(H2O)3]NO3·3DMA (JLU-MOF110(In)), [Fe3O(BHB)(H2O)3]NO3 (JLU-MOF110(Fe)), and [Fe2NiO(BHB)(H2O)3] (JLU-MOF110(FeNi)) (DMA = N,N-dimethylacetamide, H6BHB = 4,4″-benzene-1,3,5-triyl-hexabenzoic acid)}. Both JLU-MOF110(In) and JLU-MOF110(Fe) are cationic frameworks, and their BET surface areas are 301 and 446 m2/g, respectively. By modification of the components of metal clusters, JLU-MOF110(FeNi) features a neutral framework, and the BET surface area is increased up to 808 m2/g. All three MOF materials exhibit high chemical and thermal stability. JLU-MOF110(In) remains stable for 24 h at pH values ranging from 1 to 11, while JLU-MOF110(Fe) and JLU-MOF110(FeNi) persist to be stable for 24 h at pH from 1 to 12. JLU-MOF110(In) exhibits thermal stability up to 350 °C, whereas JLU-MOF110(Fe) and JLU-MOF(FeNi) can be stable up to 300 °C. Thanks to the microporous cage-based structure and abundant open metal sites, JLU-MOF110(In), JLU-MOF110(Fe), and JLU-MOF110(FeNi) have excellent CO2 capture capacity (28.0, 51.5, and 99.6 cm3/g, respectively, under 298 K and 1 bar). Interestingly, the ideal adsorption solution theory results show that all three MOFs exhibit high separation selectivity toward CO2 over N2 (35.2, 43.2, and 43.2 for CO2/N2 = 0.15/0.85) and CO2 over CH4 (14.4, 11.5, and 10.1 for CO2/CH4 = 0.5/0.5) at 298 K and 1 bar. Thus, all three MOFs are potential candidates for CO2 capture and separation. Among them, JLU-MOF110(FeNi) displays the best separation potential, as revealed by dynamic column breakthrough experiments.

Imperfect perfection: Selective induction of CO2 during diffusion in mixed matrix membranes

Imperfect perfection: Selective induction of CO2 during diffusion in mixed matrix membranes

Selective CO2 permeation properties of a membrane composed of a three-component polymer blend and cesium carbonate

ABSTRACT A high-performance CO2 separation membrane was fabricated using a composite polymer composed of a crosslinked acrylic acid polymer sodium salt, sodium polyacrylate, polyvinyl alcohol, and cesium carbonate. Evaluation tests were conducted by varying the relative humidity (RH), temperature, total pressure (Ptotal), and CO2 partial pressure (PCO2) to determine optimal parameters for enhanced performance in selective CO2 permeation over He. The membrane shows a high separation performance and durability at 50% RH and 85°C, where the CO2/He selectivity exceeds 550 under conditions of Ptotal:0.1 MPa and PCO2:0.08 MPa. Furthermore, the operational stability of the membrane was evaluated at 85°C, 50% RH, Ptotal:0.7 MPa, and PCO2:0.56 MPa. The as-fabricated membrane was stable for 300 h of continuous operation in the separation performance evaluation test. The findings of this study suggest that the developed membranes can be applied for CO2 separation from gas mixtures such as CO2/H2 with high efficiency and stability.

Heteroatom-doped noble carbon-tailored mixed matrix membranes with ultrapermeability for efficient CO2 separation.

Membranes with ultrapermeability for CO2 are desired for future large-scale carbon capture projects, because of their excellent separative productivity and economic efficiency. Herein, we demonstrate that a membrane with ultrapermeability for CO2 can be constructed by combining N/O para-doped noble carbons, C2NxO1-x, with high-permeability polymer PIM-1. The optimal PIM-1/C2NxO1-x membranes exhibit superior CO2 permeability (22110 Barrer) with a CO2/N2 selectivity of 15.5, and an unprecedented CO2 permeability of 37272 Barrer can be obtained after a PEG activation treatment, far surpassing the 2008 upper bound. Both broad experiments and molecular dynamics simulations reveal that the numerous ordered polar channels of C2NxO1-x and their excellent compatibility with PIM-1 are responsible for the superior CO2 separation performance of the membrane. Although this is the first study on C2N-type gas separation membranes, the outstanding results indicate that noble carbon building blocks may pave a new avenue to advance high-performance CO2 separation membranes.

High-performance CO2 separation membranes: comparison of graphene oxide and carboxylated graphene oxide nanofillers

High-performance CO2 separation membranes: comparison of graphene oxide and carboxylated graphene oxide nanofillers

Li-decorated β1-graphyne for high-performance CO2 capture and separation over N2

The selective CO2 adsorption is of great significance to many energy and environment-related processes. Herein, CO2/N2 adsorption and separation in Li-doped 2D graphyne allotrope (β1-GY) were studied by using grand canonical Monte Carlo simulation and density(GCMC) functional theory approaches(DFT). The results showed that Li atoms were stably combined with β1-GY and the binding energy was −2.85−−3.60 eV, which ensured the structural stability of Li-doped β1-graphyne (Li-β1-GY) for CO2/N2 adsorption and separation. Different Li doping types were evaluated, and five Li-β1-GY structures were screened, including the a, b, c, ac, and bc structures. Li doping provided more adsorption sites and improved the CO2 adsorption performance. Among all Li-β1-GYs, the ac structure showed the best CO2 adsorption performance. The CO2 adsorption capacity of ac structure reached 11.10 mmol−1 g−1 at 298 K and 100 kPa, which was higher than the well-known metal–organic framework Mg-MOF-74 (∼8.60 mmol−1 g−1) under the same condition. At 298 K and 100 kPa, the CO2/N2 selectivity reached 354. The gas distribution confirmed that CO2 was adsorbed around the Li and C atoms and demonstrated the significant improvement of C atoms around Li atoms on the CO2 adsorption. The interaction analyses showed that Li doping enhanced the CO2-framework interaction more distinctively than the N2-framework interaction, leading to an ultra-high CO2 adsorption capacity and CO2/N2 selectivity. Results of this work highlighted Li-β1-GYs as promising materials for CO2/N2 adsorption and separation.

Poly(poly(ethylene glycol) methyl ether acrylate) micelles for highly CO2 permeable membranes

Herein, we report highly CO 2 -permeable membranes obtained by blending in situ self-assembled micellar-structured poly(poly(ethylene glycol) methyl ether acrylate) (PPEGMEA) with poly(ether-block-amide) (Pebax). PPEGMEA with different molecular weights were prepared by varying the concentration of benzoyl peroxide (BPO) in a Pebax/PEGMEA/BPO mixture during radical polymerization. Significantly, the Pebax/PPEGMEA (30/70 w/w) blend membrane comprised highly CO 2 -philic PPEGMEA micelles, which appreciably increased the d -spacing of the Pebax matrix. Consequently, the blend membrane containing a high molecular weight of PPEGMEA exhibited an unprecedented CO 2 permeability enhancement of 1054% compared to the pristine Pebax membrane while maintaining good CO 2 selectivity relative to H 2 , O 2 , N 2 , CO, and CH 4 because of the enriched polyethylene glycol moieties. This excellent separation performance was maintained for 100 h, validating the good long-term separation performance of the membrane. Furthermore, the membrane exhibited good mechanical strength and plasticization tolerance, resulting in excellent CO 2 separation performance under equimolar CO 2 /N 2 or CO 2 /CH 4 mixed gas conditions (CO 2 permeability of 1250 Barrer and CO 2 /N 2 and CO 2 /CH 4 selectivity of 31.5 and 12.7, respectively), up to a CO 2 partial pressure of 10 atm. Our simple but effective in situ micelle-induced blending approach is a significant step toward realizing high-performance CO 2 separation membranes. • Poly(poly(ethylene glycol) methyl ethyl acrylates) (PPEGMEAs) were made via in-situ radical polymerization in Pebax matrix. • A high molecular weight (Mn: 57 kg/mol) of PPEGMEA formed CO 2 -philic micellar structure. • The micelles of PPEGMEA significantly enlarged d -spacing of Pebax matrix, improving CO 2 permeability by 1054%. • Pebax/PPEGMEA membrane maintained good CO 2 /gas selectivity due to the enriched PEG moieties. • Pebax/PPEGMEA membrane showed excellent CO 2 separation performance up to a CO 2 partial pressure of 10 atm.

Nitrogen Atom-Doped Layered Graphene for High-Performance CO2/N2 Adsorption and Separation

The development of high-performance CO2 capture and separation adsorbents is critical to alleviate the deteriorating environmental issues. Herein, N atom-doped layered graphene (N-MGN) was introduced to form triazine and pyridine as potential CO2 capture and separation adsorbents via regulation of interlayer spacings. Structural analyses showed that accessible surface area of the N-MGN is 2521.72 m2 g−1, the porosity increased from 9.43% to 84.86%. At ultra-low pressure, N-MGN_6.8 have exhibited a high CO2 adsorption capacity of 10.59 mmol/g at 298 K and 0.4 bar. At high pressure, the absolute adsorption capacities of CO2 in N-MGN_17.0 (40.16 mmol g−1) at 7.0 MPa and 298 K are much larger than that of N-doping slit pore. At 298 K and 1.0 bar, the highest selectivity of CO2 over N2 reached up to ~133 in N-MGN_6.8. The research shows that N doping can effectively improve the adsorption and separation capacity of CO2 and N2 in layered graphene, and the interlayer spacing has an important influence on the adsorption capacity of CO2/N2. The adsorption heat and relative concentration curves further confirmed that the layered graphene with an interlayer spacing of 6.8 Å has the best adsorption and separation ability of CO2 and N2 under low pressure. Under high pressure, the layered graphene with the interlayer spacing of 17.0 Å has the best adsorption and separation ability of CO2 and N2.

Precise regulation of CO2 packing pattern in s-block metal doped single-layer covalent organic frameworks for high-performance CO2 capture and separation

S-block metal doped single-layer polymeric tetraoxa[8]circulene (SBM-TOC, SBM = Li, Na, K, Be, Mg, and Ca) were evaluated as high-performance adsorbents for CO 2 capture and separation. Precise regulation of CO 2 packing pattern to make full use of pore space in SBM-TOCs is an effective strategy to maximize the CO 2 adsorption and separation performance. • High cohesive energy, formation energy, and bonding energy confirm high stability of SBM-TOCs. • Li-TOC exhibits excellent CO 2 uptake of 10.78 mmol/g, surpassing reported Li-doped adsorbents. • SBM doping as a polarity regulation provides adsorption sites and strong interaction. • Space regulation via SBM doping and pore size facilitates CO 2 multilayer adsorption. • The interaction between SBM and CO 2 tunes CO 2 packing pattern to exhibit a vertical configuration. The development of high-performance CO 2 capture and separation adsorbents is critical to alleviate the deteriorating environmental issues. Herein, six s-block metal doped single-layer polymeric tetraoxa[8]circulene (SBM-TOCs, SBM = Li, Na, K, Be, Mg, and Ca) were introduced as potential CO 2 capture and separation adsorbents via precise regulation of CO 2 packing patterns. Structural analyses showed that Li-TOC, Na-TOC, K-TOC, and Ca-TOC were screened with high cohesive energies ranging from 7.02 to 7.08 eV/atom and moderate formation energies ranging from –2.92 to –1.41 eV, guaranteeing their structural stabilities for CO 2 capture and separation. Electronic structure analyses confirmed the large charge transfer and strong covalent bonding characters between the SBMs and direct-connected O atoms, thus constructing a favorable gas adsorption environment. Li-TOC exhibited an ultrahigh CO 2 adsorption capacity of 10.78 mmol/g at 298 K and 1.0 bar, which was superior to previously reported Li-doped adsorbents. At 298 K and 1.0 bar, the selectivity of CO 2 over N 2 /CH 4 in Li-TOC reached up to ∼ 516 and ∼ 821, respectively. Polarity regulation analyses showed that SBMs had a more positive effect on the framework affinity for CO 2 than N 2 /CH 4 via both coulomb and van der Waals interactions. Space regulation analyses showed that strong interactions between the electropositive SBMs and the electronegative O atoms of CO 2 facilitated vertical CO 2 configurations and compact distributions, thereby rendering a multilayer CO 2 adsorption and enhancing the CO 2 adsorption capacity. Results of this work highlighted SBM-TOCs as ultrahigh-performance adsorbents for CO 2 capture and separation over N 2 /CH 4 , and demonstrated that the precise regulation of CO 2 packing pattern was an effective strategy to achieve high-performance gas capture and separation.

Self-activated, urea modified microporous carbon cryogels for high-performance CO2 capture and separation

Conventionally, porous carbons were synthesized using corrosive chemical activating agents. On contrary, we designed a single-step synthesis method for the preparation of a series of self-activated heteroatom (N)-doped carbon cryogels from potassium hydrogen phthalate (KHP) and urea at various temperatures (700–1000 °C), in the absence of any activating agent. To highlight the effectiveness of N-doping in porosity generation and CO2 adsorption/separation, a comparative analysis was drawn with a series of undoped carbon cryogels. Notably, the N-doped cryogels exhibit a highly porous structure with remarkable specific surface area (SSA; 2084 m2 g−1), micropore volume (1.1806 cm3 g−1), well-defined pore size distribution, and abundant narrow micropores (<1.04 nm). Additionally, a considerable mechanical strength (compressive strength = 0.621 MPa and compressive modulus = 8.86 MPa) was also observed. Moreover, the porous cryogel endowed with sufficient pyrrolic nitrogen content (≈51.4 at %) lead to high CO2 adsorption (280.57 mg/g at 273 K and 171.31 mg/g at 298 K at 1 bar) and an excellent ideal adsorbed solution theory (IAST)-based CO2/N2 selectivity (≈115) at 273 K, surpassing the CO2 adsorption/separation performance of previously reported N-doped carbons and resorcinol-based carbon gels. Furthermore, the moderate heat of adsorption (36.109 kJ mol−1) and stable cyclic behavior of CO2 adsorption-desorption under flue gas conditions (i.e., 15% CO2/85% N2) unveils the physisorption nature of adsorption which governs the energy-effective regeneration process. Summarizing, the present work demonstrates the successful fabrication of highly porous carbon cryogels as efficient CO2 adsorbents, thereby opening new synthetic avenues for self-activating porous carbon formation.

Multi-scale computational screening to accelerate discovery of IL/COF composites for CO2/N2 separation

• CO 2 /N 2 separation performances of IL/COF composites were examined. • IL/COF composites had two times higher selectivity and three times higher APS compared to pristine COFs. • IL/COF membranes have significantly higher CO 2 permeabilities than polymeric and zeolite membranes. Covalent organic frameworks (COFs) have emerged as novel adsorbents and membranes for gas separation. Incorporation of ionic liquids (ILs) into COFs is important to exceed the current performance limits of COFs. However, synthesis and testing of a nearly unlimited number of IL/COF combinations are simply impractical. Herein, we used a multi-scale computational screening approach combining COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) method, Grand Canonical Monte Carlo (GCMC), molecular dynamics (MD) simulations, and density functional theory (DFT) calculations to unlock both the adsorption- and membrane-based CO 2 /N 2 separation performances of IL/COF composites. Several adsorbent and membrane performance assessment metrics including selectivity, working capacity, regenerability, adsorbent performance score, and permeability were computed. Our results revealed that IL incorporation into COFs significantly improves CO 2 /N 2 adsorption selectivities (from 12 to 26) and adsorbent performance scores (from 3.7 to 12 mol/kg). By performing DFT calculations, the nature of the interactions between CO 2 , N 2 , COFs, and their IL-incorporated composites was evaluated. The high CO 2 selectivity of IL/COF composites was attributed to the cooperative intermolecular effects induced by the COF and the IL. Finally, IL/COF membranes were studied, and results showed that they achieve significantly higher CO 2 permeabilities (2.4 × 10 4 –9.4 × 10 5 Barrer) than polymeric and zeolite membranes with comparable selectivities (up to 15.7). This shows a great promise of IL/COF composites to replace the conventional membrane materials for flue gas separation. Our results will be useful in accelerating the experimental efforts to design new IL/COF composites that can achieve high-performance CO 2 separation.

Li-Decorated Β1-Graphyne for High-Performance Co2 Capture and Separation Over N2

Li-Decorated Β1-Graphyne for High-Performance Co2 Capture and Separation Over N2

Dual-function biomimetic carrier based facilitated transport mixed matrix membranes with high stability for efficient CO2/N2 separation

• Biomimetic MOFs (CFA-1) was applied to develop CO 2 /N 2 separation membrane. • The CO 2 /N 2 separation performance of the resultant membrane were markedly improved. • The Dual-function of CFA-1 on the membrane was discussed extensively. • The resultant CFA-1/Pebax membrane has superior stability. Realizing efficient carbon capture by high-performance CO 2 separation membrane is significant to mitigate the increasing emissions of greenhouse gas CO 2 . Inspired by the extraordinary CO 2 hydration ability of carbonic anhydrase (CA), a biomimetic MOF (CFA-1) which can mimic the CO 2 hydration sites of CA but possesses better stability and the lower price was incorporated into Pebax to fabricated high-performance facilitated transport mixed matrix membranes. The optimal membrane has a CO 2 permeability of 869 Barrer with a CO 2 /N 2 ideal selectivity of 88.6 at 1 bar and 30 °C, which is 9.2 times and 2.8 times than the pristine Pebax membrane. Such superior CO 2 /N 2 separation performance (far surpasses 2008 upper bound) is original from the dual-function of CFA-1: (1) provide extra pathways for gas diffusion and affinity sites for preferential CO 2 adsorption; (2) facilitate CO 2 transport in the membrane by efficiently catalyze CO 2 hydration reaction. Furthermore, the Pebax/CFA-1 membranes fabricated can also exhibit excellent stability after being treated under high temperature and harsh pH, which is not available in the Pebax/CA membranes. Overall, such biomimetic dual-function MOFs may pave a new avenue to advance the high-performance CO 2 facilitated transport membranes with excellent stability.

Bio-inspired ferromagnetic graphene oxide/magnetic ionic liquid membrane for highly efficient CO2 separation

1 Magnetic ionic liquid (MIL) was infused within the GO nano-slits 2 The dual interaction between GO and MIL enhances the magnetic ordering of MIL anion 3 The resulted GO/MILM presents nice CO 2 separation performance The design of high-performance CO 2 separation membrane with both ultrathin thickness and robust stability remains a challenge. Herein, inspired by the function of AQP1 within the biological membrane for gas selectivity, an untrathin (∼45 nm) graphene oxide/magnetic ionic liquid membrane (GO/MILM) is prepared by infusing [P 6,6,6,14 ][FeCl 4 ] into the 2D nano-space of stacked GO nanosheets. Due to the affinity difference of various gases in MIL, the synergy of electrostatic and magnetic interaction between GO and MIL, ordered arrangement of magnetic anions [FeCl 4 ] − in the nanospace between GO nanosheets is achieved, resulting efficient CO 2 separation. The molecular dynamics simulation manifests the separation mechanism. In consequence, the optimized GO/MILM exhibits fast CO 2 permeance of 82.9 GPU with high CO 2 /N 2 and CO 2 /CH 4 selectivity of 180 and 76, respectively, surpassing most of reported membranes. Moreover, a stable performance more than 7 days renders the GO/MILM great potential for industrial CO 2 separation. This bioinspired strategy may provide a potential to fabricate 2D membranes integrating high-performance, low cost and ultrathin thickness for CO 2 capture. .

Preparation of butadiene-bridged polymethylsiloxane (BBPMS)/ethyl cellulose (EC) hybrid membranes for gas separation

Hybrid membranes containing different loadings of butadiene-bridged polymethylsiloxane (BBPMS) in ethyl cellulose (EC) were prepared by an one-pot blending method from a non-isolated solution of polymethylhydrosiloxane (PMHS) reaction with butadiene, and a solution of EC in THF. The semi-crosslinked BBPMS and the BBPMS/EC hybrid membranes having good compatibility were characterized by Fourier transfer infrared (FTIR) and Scanning electron microscopy (SEM). The BBPMS/EC hybrid membranes exhibited good membrane forming ability, heat resistance and mechanical properties. It was worth mentioning that the BBPMS/EC blended membranes exhibit good selectivity for CO2/N2 and O2/N2. Specifically, the blended membrane (BBPMS/EC-5:5) showed the highest ideal selectivities for CO2/N2 and O2/N2 were 25.5 (at a CO2 permeability of 175 Barrer) and 4.85 (at a O2 permeability of 33.2 Barrer), respectively. Compared to the pure EC membrane, the ideal CO2/N4 selectivity and the ideal O2/N2 selectivity of the blended membrane (BBPMS/EC-5:5) were increased by 41.8% and 53.0%, respectively. The modification strategy using semi-crosslinked polysiloxanes to enhance gas transfer of EC is promising for fabrication of high performance CO2 and O2 separation membranes.

High performance CO2-facilitated transport membrane fabricated by compounding amine-terminated dendrimer in composite of polyvinyl alcohol and water-absorbing agent

In this study, a high-performance CO2 separation membrane was fabricated by compounding amine-based additives with composite polymers composed of polyvinyl alcohol (PVA) and water-absorbing agents. First, the separation performances of several different membranes were compared; through this process, it was found that the performance was improved when sodium polyacrylate (PAANa) was added to the membrane-forming solution. The physical properties of the membranes and their constituent materials, such as water absorbency and heat tolerance, were also evaluated. The membrane prepared by compounding amine-based additives with a composite polymer produced from PVA and PAANa demonstrated the best performance. When the membrane prepared by compounding amine-based additives with the composite polymer was used to separate a CO2–He mixture (80:20 (v/v)), the CO2/He selectivity of the membrane exceeded 600 at a total pressure of 0.1 MPa and was approximately 200 at a total pressure of 0.7 MPa at 85 °C.

First-row transition-metal-doped graphyne for ultrahigh-performance CO2 capture and separation over N2/CH4/H2

Exploring new materials with high-performance CO2 capture and separation is critical for the development of CO2 capture and utilization strategy to alleviate the excessive CO2 emissions in the atmosphere. Herein, first-row transition-metal-doped graphynes were screened according to their stability and surface flatness, and Cu-GY, Co-GY, Fe-GY, and Mn-GY were systematically evaluated. Structural analyses showed that the four TM-GYs had high cohesive energies ranging from 7.07 to 7.35 eV/atom, moderate formation energies ranging from −6.83 to −3.28 eV, large diffusion barriers of the TM atoms ranging from 2.25 to 3.48 eV, which guaranteed their structural stabilities for CO2 capture and separation. Electronic structure analyses confirmed the evident orbital overlap, large charge transfer, and strong covalent bonding characters between the TMs and direct-connected C atoms, thus constructing a favorable gas adsorption environment. Cu-GY exhibited ultrahigh CO2 adsorption capacity of 8.46 mmol/g at 298 K and 1.0 bar, which was larger than ever reported results in slit pores and comparable to the highest adsorption capacity of 8.60 mmol/g in Mg-MOF-74 under the same conditions. At 298 K and 1.0 bar, the selectivities of CO2 over N2/CH4/H2 in Cu-GY reached up to 913, 331, and 2641, respectively. Interaction analyses proved that the CO2 interaction with frameworks via both Coulomb and van der Waals was greater than those of the other gases. Strong affinity of CO2 with Cu-GY relative to other TM-GYs and large isosteric heat differences between CO2 and other gases rendered Cu-GY to possess the ultrahigh CO2 adsorption capacity and remarkable selectivity over N2/CH4/H2. Gas distribution analyses exhibited the wide CO2 distribution composed of multilayer adsorption peaks around the TMs and adjacent C atoms, elucidating the significant effect of the TMs and TM-connected C atoms on CO2 adsorption. Results of this work highlighted TM-GYs as ultrahigh-performance adsorbents for CO2 capture and separation over N2/CH4/H2.