Adsorption Separation Research Articles

Oriented 1D Metal-Organic Frameworks for Selective Chemisorption by a Substitution-Insertion Mechanism.

Chemisorption on organometallic-based adsorbents is crucial for the controlled separation and purification of targeted systems. Herein, oriented 1D NH2-CuBDC·H2O metal-organic frameworks (MOFs) featuring accessible CuII sites are successfully fabricated by bottom-up interfacial polymerization. The prepared MOFs, as deliberately self-assembled secondary particles, exhibit a visually detectable coordination-responsive characteristic induced by the nucleophilic substitution and competitive coordination of guest molecules. As a versatile phase-change chemosorbent, the MOFs exhibit unprecedented NH3 capture (18.83 mmol g-1 at 298 K) and bioethanol dehydration performance (enriching ethanol from 99% to 99.99% within 10 min by direct adsorption separation of liquid mixtures of ethanol and water). Furthermore, the raw materials for preparing the 1D MOFs are inexpensive and readily available, and the facile regeneration with water washing at room temperature effectively minimizes the energy consumption and cost of recycling, enabling it to be the most valuable adsorbent for the removal and separation of target substances.

Theoretical investigations on the purification of petroleum using desulfurization process: Analysis and optimization of process

This paper introduces a comprehensive approach for predicting chemical concentrations (C) of sulfur compound in a two-dimensional space (x, y) by numerical solution of mass transfer equation and integration of machine learning. Data of training/validation are obtained from mass transfer modeling on adsorption separation utilizing porous adsorbent for petroleum desulfurization. Mass transfer modeling data were utilized for machine learning models which included three different regression models, namely Support Vector Machine (SVM), Decision Tree Regression (DT), and Multilayer Perceptron (MLP). The hyper-parameters of these base models were optimized using the Grey Wolf Optimization (GWO) algorithm. The ensemble models, denoted as ADA-DT, ADA-MLP, and ADA-SVM were assessed based on key performance metrics, including R2, MAE, RMSE, and MAPE. Results demonstrated the efficacy of the ensemble models in capturing complex relationships within the dataset. ADA-DT obtained an exceptional R2 score of 0.99031, highlighting its outstanding predictive accuracy. Similarly, ADA-MLP and ADA-SVM showed great accuracy, achieving R2 of 0.88272 and 0.96842, respectively. In this study, we uncover valuable insights into the application of ensemble methods and hybridized optimization methods for accurate and robust regression modeling in chemical concentration prediction scenarios applicable for petroleum engineering.

Positively Photo-Responsive Adsorption Over Binary Copper Porphyrin Framework and Graphene Film Sorbents.

Photo-responsive adsorption has emerged as a vibrant area because it provides a promising route to reduce the energy consumption of the traditional adsorption separation. However, the current methodology to fabricate photo-responsive sorbents is still subject to the photo-deforming molecular units. In this study, a new initiative of photo-dissociated electron-hole pairs is proposed to generate amazing adsorption activity, and prove its feasibility. Employing CuPP [PP = 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin] framework nanosheets compounded with graphene, binary film (BF) sorbents are successfully fabricated. The paradigmatic BF nanostructure brings about efficiently photo-excited electron-hole pairs with durable enough lifetime to meet the needs of microscopic adsorption equilibrium, which ultimately alters the electron density distribution of adsorption surface, and thus markedly modulates the adsorption activity. Therefore, an amazing photo-enhanced adsorption capability for the index gas CO can be gotten. Once exposed to the visible-light at 420nm, the CO adsorption capacity (0°C, 1bar) is risen from 0.23mmolg-1 in the darkness to 1.66mmolg-1, changed by+622%. This is essentially different from majority of current photo-responsive sorbents based on photo-deforming molecular units, of which adsorption capability is only decreased with photo-induction, and the maximum rate of change reported is just -54%.

A MOF built on 8-connected Y3 nodes demonstrates simultaneous reverse adsorptive separation: ethane over ethylene and propane over propylene

A MOF built on 8-connected Y3 nodes demonstrates simultaneous reverse adsorptive separation: ethane over ethylene and propane over propylene

Efficient adsorption and selective separation of high value-added chemicals from simulated expired energy drinks by metal-organic frameworks

Expired energy drinks contain a certain amount of high-value chemicals, such as caffeine, that possess biological activity. The recovery and recycling of these valuable chemicals plays a crucial role in promoting the achievement of carbon emission reduction goals. In this work, 11 kinds of water-stable MOFs with different pore channel structure were synthesized and used for the first time to adsorb caffeine, nicotinic acid, or taurine from water. It has been found that the size effect of the topological structure of MOF adsorbents is the fundamental factor governing their adsorption performance. The optimized adsorbent UiO-67 exhibits excellent adsorption performance for caffeine and nicotinic acid, with respective adsorption capacities of 830 mg/g and 583 mg/g. The investigated MOF has a very low adsorption capacity for taurine (48 mg/g); therefore, selective separation of caffeine/taurine and nicotinic acid/taurine was achieved. The adsorption process can be accurately described by both the Langmuir model and pseudo-second-order model. Adsorption mechanism reveals that the main driving forces of the adsorption process are π-π interaction between UiO-67 and CN in caffeine, as well as hydrogen bonding interactions between the N atom of caffeine’s two CO groups and μ-OH of UiO-67.

Comparison of upward and downward flow in high-pressure bulk CO2 gas adsorption on NaY zeolite fixed bed

Adsorption is an appealing technology for the removing of CO2 from natural gas because it can handle high CO2 concentrations at high pressures. The determination of mono-component breakthrough curves provides heat and mass transfer parameters to assess separation effectiveness that can be used for simulation of swing adsorption separation processes (PSA, TSA etc.). However, in lab-scale fixed-bed adsorption, it may be challenging to perform this assessment due to low flow conditions that are usually employed, affecting the flow regimedepending on the operation conditions. In this sense, this work aimed to evaluate the effect of flow regime configurations and difference in gases densities by means of residence time distribution (RTD) analysis in the PSA of CO2 in a NaY zeolite fixed bed , in order to to collect information that satisfy pipeline specifications in industrial applications. A high-pressure lab-scale apparatus was used with NaY particles of 0.7250 mm mean diameter, a 10.5 cm bed height , and a tubular column of 2.0 cm internal diameter. The upward and downward flows were conducted under 528.82 ± 4.59 NmL min−1 inlet mass flow rate, 51 bar, and 30 °C. The RTD analysis was performed to verify the flow regime, and mass transfer zone (MTZ) length was estimated. It was observed that downward flow conditions promoted higher concentration spread than upward flow. RTD analysis showed that downward flow is dominated by laminar convection while the upward flow is dominated by dispersion. MTZ length increased from 0.64 cm in upward flow to 5.81 cm in downward flow. Therefore, assessing CO2 flow conditions and, additionally, the difference in gases densities, are important steps that should be taken when dealing with fluid adsorption under high pressure because different densities between fluid components severely changed and affected flow regime and, consequently, separation effectiveness.

Apple Tree Root‐Derived Biochar/Iron Oxide Triphasic Nanocomposite for Wastewater Treatment and Microwave Absorption

AbstractIn this work, two major sources of pollution: (1) Water pollution due to heavy metals, and (2) Electromagnetic wave (EMW) pollution, often regarded as the fourth category of pollution (after air, water, and soil pollution) are addressed. A unique bio‐based triphasic nanocomposite (Fe3O4/α‐Fe2O3/carbon) is synthesized and its superior properties are demonstrated to address both types of environmental pollution. The nanocomposite, derived from lightweight apple tree roots, is used for Pb (II) ion removal from aqueous solutions via adsorption and magnetic separation. The biomass‐derived highly porous biochar decorated with iron‐oxide showed adsorption efficiency of nearly 100% and corresponding capacity of 149 mg.g−1 under optimal conditions for initial Pb (II) concentration of 50 mg.L−1. Furthermore, a remarkable adsorption capacity of 731 mg.g−1 is achieved using lower amount of the adsorbent for a slightly lower efficiency (97%). In addition, the mesoporous composite showed excellent EMW absorption efficiency with effective absorption bandwidth of 7.8 GHz and reflection loss of −61.7 dB, arising from very good impedance matching, and high dielectric and magnetic losses. This work establishes the multifunctional properties of the synthesized composite, and addresses the UN Sustainable Development Goal (SDG) 6 (Clean water and sanitation) and SDG 13 (Climate action, including pollution management).

Separation of 2,3-Butanediol from Fermentation Broth via Cyclic and Simulated Moving Bed Adsorption Over Nano-MFI Zeolites.

The biomass-based platform molecule 2,3-butanediol (2,3-BDO) has a wide range of applications in production of sustainable fuels, chemicals, synthetic rubber, and others. However, the selective separation of 2,3-BDO from multicomponent fermentation broths presents challenges due to its low concentration, high solubility in water, high boiling point, and presence of many other species. Here, we demonstrate remarkably selective enrichment and recovery of 2,3-BDO from a corn stover hydrolysate fermentation broth by a pure-silica nano-MFI-type zeolite adsorbent. By means of cyclic and simulated moving bed adsorption processes, we obtained concentrated aqueous 2,3-BDO streams from the fermentation process stream with ∼93% purity and 3-fold enrichment, and >98% purity and 8-fold enrichment, respectively. These findings provide strong support for large-scale adsorptive separation for biobased 2,3-BDO production.

Multifunctional and Ultrastable Co-MOF Effectively Separates Various Different Component Gas Mixtures.

Developing low-cost and multifunctional adsorbents for adsorption separation to obtain high-purity (>99.9%) gases is intriguing yet challenging. Notably, the ongoing trade-off between adsorption capacity and selectivity in separating multicomponent mixed gases still persists as a pressing scientific challenge requiring urgent attention. Herein, the ultrastable TJT-100 exhibits unique structural characteristics including uncoordinated carboxylate oxygen atoms, coordinated water molecules directed toward the pore surface, and sufficient Me2NH2+ cations in channels. TJT-100 exhibits a high adsorption capacity and exceptional separation performance, particularly notable for its high C2H2 capacity of 127.7 cm3/g and remarkable C2H2 selectivity over CO2 (5.4) and CH4 (19.8), which makes it a standout material for various separation applications. In a breakthrough experiment with a C2H2/CO2 mixture (v/v = 50/50), TJT-100 achieved a record-high C2H2 productivity of 69.33 L/kg with a purity of 99.9%. Additionally, TJT-100 demonstrates its effectiveness in separating CO2 from natural gas and flue gas. Its exceptional selectivity for CO2/CH4 (10.7) and CO2/N2 (11.9) results in a high CO2 productivity of 21.23 and 22.93 L/kg with 99.9% purity from CO2/CH4 (v/v = 50/50) and CO2/N2 (v/v = 15/85) mixtures, respectively.

Synthesis of Fe2O3/TiO2 Photocatalytic Composites for Methylene Blue Degradation as a Novel Strategy for High-Value Utilisation of Iron Scales.

In this study, novel Fe2O3/TiO2 photocatalytic composites were synthesised by combining traditional oxidation roasting with the sol-gel method, using low-cost metallurgical waste (iron scales) as the raw material. The characterisation results revealed that the oxidised iron scales could be transformed into high-purity and porous Fe2O3 particles through oxidation roasting, thereby providing additional sites for the adsorption process and thus serving as an effective carrier for TiO2-based photocatalytic materials. During the sol-gel process, TiO2 was loaded onto the synthesised Fe2O3 particles, generating core-shell heterostructure Fe2O3/TiO2 photocatalytic composites. Under visible light irradiation for 90 min, the Fe2O3/TiO2 photocatalytic composites achieved a remarkable methylene blue removal rate (97.71%). This reaction process followed the quasi-first-order kinetic model with a rate constant of 0.038 min-1. The results have demonstrated that this combination of various components in the Fe2O3/TiO2 photocatalytic composites improved the adsorption, light utilisation, and charge separation effect of the photocatalysts. Moreover, the material exhibited favourable stability and recyclability, making it a decent candidate for the treatment of wastewater from the biochemical industry. Therefore, this study provides a new strategy for improving the photocatalytic activity of TiO2 and expanding the high value-added utilisation of iron scales.

Extraction of sustainable and low-emission hydrogen from hydrogen-blended natural gas driven by multi-product sequential separation

Blending hydrogen in natural gas, taking advantage of the readily available pipeline transportation, is considered as a highly promising means of sustainable hydrogen deployment on a vast scale. However, re-obtaining hydrogen from the mixture for end users via conventional separation technologies could pose practical challenges both energetically and economically, due primarily to the relatively low blending ratio (<30 vol%). In contrast to the commonly adopted pressure swing adsorption (PSA) separation, we propose a thermochemical approach of deriving hydrogen with synergistic capture of CO2 by steam reforming of the mixture to tackle such challenges. The process is simulated by a two-dimensional model validated by experimental data. Three typical scenarios with hydrogen blending ratios of 0–30 vol% are investigated in the operating temperature range of 300–400 °C and natural gas pipeline pressure of ≤ 40 bar. Results show that in all scenarios the amount of hydrogen recovered can exceed the amount of renewable hydrogen initially blended and additional hydrogen could be contributed thermochemically, all at relatively low energy cost. Thermochemical methods increase the partial pressure of target products, reducing separation energy and increasing yield. For the typical 10 vol% blending ratio (widely adopted), when considering the separation of hydrogen at the end user and compressing the separated off-gas before transporting it to the next end user, the hydrogen separation cost, after counterbalancing with the revenue from carbon dioxide, is only 1.33$/kgH2 with the new approach. This corresponds to a decrease by over 70.2 % as compared with that of the PSA separation cost (4.45$/kgH2). The captured CO2 in its high-purity form helps to reduce the final cost of hydrogen by a maximum of 0.33$/kgH2. The new route shows great potential for integrated hydrogen production, hydrogen purification and carbon capture for the promotion of renewable energy, green hydrogen and related technologies.

Adsorption characteristics and separation behavior of binder and binderless zeolite LiX Pellets: O2, N2, and CO2

In adsorptive gas separation process design, optimal adsorbent selection acts as a critical factor in process efficiency. This study investigated the adsorption equilibria and kinetics of O2, N2, and CO2 (weak, medium and strong affinity, respectively) and the breakthrough performance of four commercial zeolite LiX pellets (one binderless and three binder zeolite LiX pellets) because the performance of pelletized zeolites becomes different by adding binders and pelletizing methods. The adsorption isotherms at 293–323 K and up to 100 kPa were correlated with the dual-site Langmuir and Sips models. For all adsorbents, the order of adsorption amount and isosteric heat of adsorption was CO2 ≫ N2 > O2. However, differences among the four zeolite pellets were also observed, showing the highest values of the binderless zeolite LiX pellet. Furthermore, the adsorption capacity was 20–25 % smaller for CO2 and 40–50 % smaller of N2 and O2 at 100 kPa compared to pure zeolite LiX powder. According to kinetic analysis using a non-isothermal diffusion model, the adsorption rate of N2 was faster than that of CO2 for all adsorbents, showing the order difference in the low-pressure range. The kinetic difference among the zeolite pellets resulted from the effects of heat of adsorption, heat dissipation, and thermal resistance. The breakthrough performance using N2 and O2 was mainly controlled by the adsorption capacity, showing almost constant breakthrough pattern regardless of the samples. This study suggests that detailed evaluation of pelletized adsorbent is essential before designing adsorptive processes because performance of adsorbent powder would lead to under-design of the process. (255 words)

Preparation of Guanidine-Grafted NH2-MIL-101(Fe)/Polyvinylidene Fluoride Mixed Matrix Membranes for Adsorption of Pb2+ for Isopropanol Purification.

Electronic-grade isopropyl alcohol is widely utilized in the cleaning of semiconductors and microelectronic components. Removing ions like Pb2+ is crucial since the presence of impurities may cause degradation of electronics, increased failure rates, and short circuits. Membrane materials offer a number of advantages in the field of adsorption separation; however, the lack of adsorption sites results in limited adsorption capacity. In the current work, guanidino-grafted NH2-MIL-101(Fe) was incorporated into polyvinylidene fluoride (PVDF) to prepare MOF/PVDF mixed matrix membranes (NM/PVDF) for the removal of Pb2+ from isopropanol. Benefiting from the larger specific surface area and more lone electron pairs in the guanidine group, the Pb2+ adsorption capacity of the as-prepared NM/PVDF membrane was 29.4458 mg/g, which was higher than that of the NH2-MIL-101(Fe)/PVDF membrane (20.9306 mg/g) and the pure PVDF membrane (6.7324 mg/g). The NM/PVDF membrane was able to reduce the concentration of Pb2+ from 500 to 86.73 ppb. This work highlights the potential of guanidine-grafted Fe-based MOFs/PVDF membranes as adsorbents for acquisition of electronic-grade solvents.

Construction of a Methoxy-Functionalized Pillar-Layer Metal-Organic framework for low-concentration SO2 uptake and adsorption separation

We report the synthesis and structural characterization of a novel methoxy (–OCH3) −functionalized pillar-layer metal–organic framework (MOF), denoted as DZU-17 (DZU=Dezhou University), which is isoreticular to Co6-MOF-3. DZU-17 is constructed by integrating a –OCH3 modified bipyridine ligand, 1,4-dipyridine-2,5-dimethoxybenzene (BPB-OCH3), into the framework of Co6-MOF-3. Single-crystal X-ray diffraction analysis confirms that the introduction of the –OCH3 groups effectively partitions the spacious channels of Co6-MOF-3 into more confined spaces within DZU-17. This structural modification results in a significant enhancement in SO2 uptake at low −pressure (P=0.1 bar, 112.7 cm3 g−1) and improved separation capacity for SO2/CO2/N2 mixture under ambient conditions. Our findings underscore the potential of functional group engineering on MOF linkers to modulate pore dimensions and chemical environments, thereby enhancing the frameworks’ performance in gas adsorption and separation processes.

Aromatic pore engineering in microporous metal–organic frameworks for high-production one-step methane purification from ternary alkanes mixtures

The exploitation of competent isolation and purification technology of methane (CH4) is an imperative and challenging task for full utilization of clean natural gas in petrochemical industry. Compared to traditional energy-intensive low-temperature distillation, adsorptive separation using porous metal–organic framework (MOF) materials provides an alternative technique with low energy consumption and high efficiency. In this situation, an aromatic pore engineering strategy in a series of pillar-layered Zn-based MOFs by introducing organic linkers with different degrees of aromatic units was investigated to tune pore size and pore environment for simultaneously removing propane (C3H8) and ethane (C2H6) from C3H8/C2H6/CH4 mixtures. Compared to the other two analogues, i.e. Zn(BDC)(TED)0.5 and Zn(ADC)(TED)0.5, obtained Zn(NDC)(TED)0.5 showed high adsorption capacity for C3H8 (5.18 mmol/g) and C2H6 (5.04 mmol/g) and selectivity for C3H8/CH4 and C2H6/CH4 at 298 K and 1.0 bar. Breakthrough tests proved the three MOFs can effectively separate ternary C3H8/C2H6/CH4 mixtures, and Zn(NDC)(TED)0.5 especially exhibited excellent high-purity CH4 yield of 10.07 mmol/g. Computational simulations showed that suitable pore space and surface aromatic environment in Zn(NDC)(TED)0.5 created beneficial interactions with C3H8 and C2H6 molecules, which ultimately contributed to its favourable adsorption and separation property. This system work provides insights for the development of pore control method in MOF materials for natural gas purification.

Efficient adsorptive separation of Cu(II) from Ph by ZIF-8 constructed with sodium alginate polymer backbone

With the rapid development of industrialization, the removal of heavy metal ions and small organic molecules from wastewater has triggered a hot debate. ZIF-8 was grown on a sodium alginate backbone using an in situ growth technique, the core-shell P-SMG@ZIF-8 was synthesized. It was also characterized by FTIR, XRD, SEM, UV–Vis and XPS, and the optimal conditions and mechanism of adsorption were explored. At pH 2.0, a contact time of 200 min, and 298 K, removal of Cu(II) and Ph up to 80.2 %, 65.6 % by P-SMG@ZIF-8, adsorption behavior consistent with Langmuir model for pseudo-secondary rates, the saturated adsorption of Cu(II) and Ph could reach up to 83.5812 mg/g and 78.1779 mg/g, respectively. And the adsorbed P-SMG@ZIF-8 is easy to separate and reusable, which is a cost-effective and efficient natural product-based adsorption material.

Separation of C6 hydrocarbons on sodium dithionite reduced graphene oxide aerogels

The ability of reduced graphene oxide aerogels (rGOAs) for challenging gas-phase separation was investigated with hexane isomers and benzene (C6 hydrocarbons) using inverse gas chromatography (IGC). For the first, rGOAs were synthesized with sodium dithionite (DTN) as a reductant. Experiments revealed that the most optimal DTN to graphene oxide mass ratio was 2:1, resulting in the highest specific surface area of 432.3 m2 g−1 and the highest degree of graphitization among analyzed samples. C6 hydrocarbon adsorption tests demonstrated the dominant role of the kinetic effect for the adsorption of branched and cyclic hexane isomers - the partition coefficient decreased as the molecule kinetic diameter increased. The contribution of thermodynamic effects was distinguished for molecules with uneven charge distribution. A comparison of the partition coefficient ratios for different pairs of hydrocarbons demonstrated the potential of rGOAs in separating various C6 hydrocarbons. The selectivity, calculated from binary-component adsorption tests of benzene (Bz)/cC6 equimolar mixture, was 13.7, 8.5 and 2.8 for DTN4, DTN2, and DTN1. The research indicates that rGOAs may have potential as adsorbents for the selective separation of hydrocarbons, however, the competitive adsorption and performance at high surface coverages of adsorbates have to be accounted for in further research to assess the applicability of rGOAs reliably.

Integration of deep eutectic solvent with adsorption and membrane-based processes for CO2 capture: An innovative approach

CO2 capture strategies have been implemented to address climate change by reducing CO2 emissions from large-scale sources such as fossil fuel power plants and natural gas upgrading. Deep eutectic solvents (DESs) are a new class of green solvents with good CO2 affinity, simple synthesis steps, inexpensive raw materials, non-toxic and non-volatile properties. For these reasons, they are a promising platform for CO2 capture applications and have tremendous untapped potential to enhance the performance of the adsorption and membrane-based separation processes. Unlike existing reviews which have focused on the functionalities of DESs, as well as the physicochemical and CO2 solubility properties of DESs, this mini-review discusses the integration of DESs with adsorption and membrane processes to evaluate their CO2 separation performance. Moreover, simulation and computational studies on DES-based systems, including confinement in porous solids and membranes, are discussed. Finally, perspectives on developing DES-based adsorbents and DES-based membranes for the CO2 separation field are presented. This review provides insight into the potential of integrating DESs with CO2 capture technologies to enhance the performance of hybrid systems in relation to standalone approaches.

Adsorption of haem by magnetic chitosan microspheres: Optimal conditions, adsorption mechanisms and density functional theory analyses

Magnetic chitosan microspheres (Al@CTS@Fe3O4) were prepared for haem separation via chemical cross-linking of chitosan, Fe3O4 and AlCl3·6H2O. The properties of the Al@CTS@Fe3O4 microspheres were investigated through techniques including XRD, TEM, FTIR, BET analysis, SEM, TG, VSM, XPS and pHpzc analysis. The haem adsorption of Al@CTS@Fe3O4 was optimized via a Box–Behnken design (BBD) with three operating factors: Fe3O4 dose (0.5–1.3 g), AlCl3·6H2O concentration (0.25–1.25 mol/L) and glutaraldehyde dose (2–6 mL). The optimal haem adsorption effect was achieved with 1.1 g of Fe3O4, 0.75 mol/L AlCl3·6H2O, and 3 mL of glutaraldehyde. The adsorption kinetics and isotherms demonstrated that haem adsorption by the Al@CTS@Fe3O4 microspheres was best described by the pseudo-second-order model. The maximum adsorption capacity is 33.875 mg/g at pH 6. After six adsorption–desorption cycles, the removal of haem still reached 53.83 %. The surface adsorption mechanism of haem on Al@CTS@Fe3O4 can be attributed to electrostatic, hydrogen bonding, and n-π interactions. Thermodynamic calculations indicated that the adsorption process is spontaneous, with the microspheres preferentially accepting electrons and haem preferentially providing electrons. Consequently, the Al@CTS@Fe3O4 microspheres exhibit considerable potential as adsorbents for haem separation.

Understanding pore features of pillar-layered MOFs on one-step C2H4 purification from C2H6/C2H4 mixtures

Purification of ethylene from ethane through adsorption separation is a key industrial process in present chemical field, since the similar physical properties of both C2H4 and C2H6 that makes them difficult to separate. Therefore, constructing C2H6-selective adsorbents and clarifying its structure–activity relationship is a very difficult undertaking. In this study, 3D pillar-layered metal organic frameworks (MMOF-kgm (M = Zn, Co, Ni) and NiMOF-sql) with different topologies, kagome and square lattice, were constructed by using the cheap ligands (1,4-benzenedicarboxylic acid and triethylenediamine). The effect of pore features on C2H6/C2H4 separation performance and the separation mechanism were systematically investigated by the above two isomeric MOFs. In particular, NiMOF-kgm with kagome topology provides narrower triangular pore shows notably adsorption of C2H6 over C2H4, which is validated by gas adsorption, IAST selectivity and breakthrough measurements. The selective adsorption mechanisms of MOF with kagome topology were further revealed through DFT calculations. This study provides in-depth insights into optimizing the pore structure of MOFs to enhance C2H6/C2H4 separation performance, offering new design strategies for developing efficient materials for ethane-selective adsorbent for one-step ethylene purification.