Search

Effective separation of hexane (C6) isomers is critical for a variety of industrial applications but conventional distillation methods are energy‐intensive. Adsorptive separations based on porous coordination polymers (PCPs) offer a promising alternative due to their exceptional porosity and tunable properties. However, there is still an urgent need to develop PCPs with high stability and separation performance. This study investigates how substituting a methyl (−CH3) group with a trifluoromethyl (−CF3) group can regulate pores and hydrophobicity in PCPs. This precise adjustment aims to enhance stability and improve the kinetic separation performance of hydrophobic C6 isomers by considering the size and hydrophobicity of the trifluoromethyl group. Two isostructural PCPs with pcu topology, PCP‐CH3 and PCP‐CF3, were synthesized to vary pore diameters and hydrophobicity based on the presence of −CH3 or −CF3 groups. PCP‐CF3 showed greater stability in water compared to PCP‐CH3. While PCP‐CH3 had high adsorption capacities, it lacked selectivity, whereas PCP‐CF3 demonstrated improved selectivity, particularly in excluding dibranched isomers. Dynamic column separation experiments revealed that PCP‐CF3 could selectively adsorb linear and monobranched isomers over dibranched isomers at room temperature. These findings highlight the potential of fluorine‐modified PCPs for efficient isomer separation and underscore the importance of stability improvement strategies. [ABSTRACT FROM AUTHOR]

To control the emission of SO2 from flue gas into the atmosphere while considering the capture and collection of greenhouse gas CO2, the adsorption behavior of a binary mixture of SO2 and other gases in flue gas (O2/N2/H2O/CO 2) in (10, 10) carbon nanotube (CNT) was simulated using grand canonical Monte Carlo (GCMC) simulation. The adsorption and separation performance of SO2 in CNTs with a diameter range of 0.81–1.63 nm for the five-component mixture gas was also analyzed. The findings suggest that the adsorption and separation of SO2 are primarily influenced by CO2 (reduction of adsorption capacity by about 50%, separation coefficient of SO2/CO2 is lowest) with this effect being more pronounced under high pressure. Meanwhile, it was observed that CNTs with larger pipe diameters exhibit higher SO2 adsorption capacity, but relatively lower SO2/CO2 selectivity and lower stability. On the other hand, CNTs with smaller diameters have relatively lower adsorption capacity for SO2, but exhibit good selectivity and stability (under different pressure) for SO2/CO2. Based on the statistical analysis of SO2 adsorption capacity and SO2/CO2 selectivity, it was determined that (6, 6) CNT with a diameter of 0.81 nm can exhibit excellent SO2 adsorption and separation performance at atmospheric pressure, while appropriate large diameter CNTs should be selected for flue gas treatment under high pressure. [ABSTRACT FROM AUTHOR]

Biofuels offer significant potential for reducing carbon emissions and enhancing energy sustainability, but their efficient purification remains a significant challenge. In this study, the performance of a hydrophobic zeolitic imidazolate framework, ZIF-71(ClBr)-SE, in the adsorptive separation of butanol from single- and ternary-component systems (acetone, butanol, and ethanol) was investigated and compared with ZIF-8 and ZIF-71. Physicochemical characterization techniques, including XRD, SEM, BET, TGA, and DVS, confirmed that the modified ZIF-71 is hydrophobic, isostructural with ZIF-71, and has a higher surface area. Adsorption tests in aqueous solutions revealed that ZIF-71(ClBr)-SE unexpectedly showed a higher affinity for acetone over butanol. DFT molecular simulations provided insights into solute-ZIF interactions, highlighting preferential sites for ZIF interaction. [ABSTRACT FROM AUTHOR]

The synthesis of zirconium MOFs with zeolite net is quite challenging due to the high connectivity of Zr6 clusters, which is far from tetrahedral connection, a requisite for zeolite net. In this work, we demonstrate a six‐membered ring (6MR) strategy through mimicking of mineral zeolites with mixed ditopic and tritopic carboxylate linkers. With this strategy, the ditopic linker cross‐links Zr6 clusters to form 4‐connected zeolite‐like nets, while the tritopic one is used to direct the formation of 6MR and simultaneously consumes extra coordination sites on the cluster. The feasibility of this strategy is shown by one zeolitic metal–organic framework (NNM‐5) and this strategy has also led to the synthesis of the other dia‐type zirconium MOF (NNM‐6). Interestingly, as the tritopic linker not only directs the formation of 6MR but also partitions 6MR into small segments, NNM‐5 with SOD topology shows a structural feature of small aperture and big cage, which has led to efficient separation of hexane isomers. With both exceptionally high n‐hexane uptake (65.9 cm3 g−1) and size‐exclusion selectivity, an exceptional separation capability is verified by breakthrough experiments. Calculation results demonstrate that the large difference of diffusion energy barrier due to the small aperture accounts for the underlying separation mechanism. [ABSTRACT FROM AUTHOR]

Due to almost identical boiling points of benzene and cyclohexane, the extraction of trace benzene from cyclohexane is currently performed via the energy-intensive extractive distillation method. Their adsorptive separation by porous materials is hampered by their similar dimensions. Metal-organic frameworks (MOFs) with versatile pore environments are capable of molecular discrimination, but the separation of trace substrates in liquid-phase remains extremely challenging. Herein, we report a robust MOF (NKU-300) with triangular channels decorated with crown ether that can discriminate trace benzene from cyclohexane, exhibiting an unprecedented selectivity of 8615(10) for the mixture of benzene/cyclohexane (v/v = 1/1000). Remarkably, NKU-300 demonstrates exceptional selectivities for the extraction of benzene from cyclohexane over a wide range of concentrations of 0.1%–50% with ultrafast sorption kinetics and excellent stability. Single-crystal X-ray diffraction and computational modelling reveal that multiple supramolecular interactions cooperatively immobilise benzene molecules in the triangular channel, enabling superior separation performance. This study will promote the application of advanced sorbents with tailored binding sites for challenging industrial separations. [ABSTRACT FROM AUTHOR]

The wastewater from an electroplating industry contains chromium VI which is highly carcinogenic at a typical level of 21.5 to 47 mg L−1 which should be reduced to acceptable value of 0.05 mg L−1 for the water to be suitable for drinking purpose. In this study, Tulsion A23 resin was applied as an adsorbent for successful removal of Cr(VI), also dealing with understanding the effect of various parameters on extent of removal of the contaminant. It was elucidated that contact time of 120 min is required for the equilibrium and the optimum pH value was 5 and the optimum resin loading was 4 g L−1 at which 97% Cr(VI) removal was observed. Different adsorption isotherm models were applied and it was elucidated that Langmuir model was the best fit with R2 as 0.99. In the case of kinetic study, pseudo‐second order model was best fitted with higher R2 value. The regeneration of the resin was performed using 3 M NaOH and it was shown that after the three cycles of regeneration, the resin showed 82% Cr(VI) removal. Overall, successful application of Tulsion A23 resin was demonstrated for the removal of Cr(VI) from real effluent for the first time. [ABSTRACT FROM AUTHOR]

The direct one-step separation of polymer-grade C2H4 from complex light hydrocarbon mixtures has high industrial significance but is very challenging. Herein, an ethylene-adsorption-weakening strategy is applied for precise regulation of the pore geometry of four tailor-made metal–organic frameworks (MOFs) with pillar-layered structures, dubbed TYUT-10/11/12/13. Based on its pore geometry design and functional group regulation, TYUT-12 exhibits exceptional selective adsorption selectivity toward C3H8, C3H6, C2H6, C2H2, and CO2 over C2H4; its C2H6/C2H4 adsorption selectivity reaches 4.56, surpassing the record value of 4.4 by Fe2(O2)(dobdc) (dobdc4− = 2,5-dioxido-1,4-benzenedicarboxylate). The weak π–π stacking binding affinity toward C2H4 in TYUT-12 is clearly demonstrated through a combination of neutron powder diffraction measurements and theoretical calculations. Breakthrough experiments demonstrate that C2H4 can be directly obtained from binary, ternary, quaternary, and six-component light hydrocarbon mixtures with over 99.95% purity.

Xylene separation is crucial but challenging, especially for the preferential separation of the intermediate‐size m‐xylene from xylene mixtures. Herein, exploiting the differences in molecular length and alkyl distribution among xylenes, we present a length‐matched metal–organic framework, formulated as Al(OH)[O2C−C4H2O−CO2], featuring an effective pore size corresponding to m‐xylene molecular length combined with multiple negative O hydrogen bond donors distribution, can serve as a molecular trap for efficient preferential separation of the intermediate‐size m‐xylene. Benchmark separation performance was achieved for separating m‐xylene from a ternary mixture of m‐xylene/o‐xylene/p‐xylene, with simultaneous record‐high m‐xylene uptake (1.3 mmol g−1) and m‐xylene/p‐xylene selectivity (5.3) in the liquid‐phase competitive adsorption. Both vapor‐ and liquid‐phase fixed‐bed tests confirmed its practical separation capability with benchmark dynamic m‐xylene/p‐xylene and m‐xylene/o‐xylene selectivities, as well as excellent regenerability. The selective and strong m‐xylene binding affinity among xylene molecules was further elucidated by simulations, validating the effectiveness of such a pore environment for the separation of intermediate‐size molecules. [ABSTRACT FROM AUTHOR]

Adsorptive C2H2/C2H4 separation using metal–organic frameworks (MOFs) has emerged as a promising technology for the removal of C2H2 (acetylene) impurity (1 %) from C2H4 (ethylene). The practical application of these materials involves the optimization of separation performance as well as development of scalable and green production protocols. Herein, we report the efficient C2H2/C2H4 separation in a MOF, Cu(OH)INA (INA: isonicotinate) which achieves a record C2H2 packing density of 351 mg cm−3 at 0.01 bar through high affinity towards C2H2. DFT (density functional theory) calculations reveal the synergistic binding mechanism through pore confinement and the oxygen sites in pore wall. The weakly basic nature of binding sites leads to a relatively low heat of adsorption (Qst) of approximately 36 kJ/mol, which is beneficial for material regeneration and thermal management. Furthermore, a scalable and environmentally friendly synthesis protocol with a high space‐time yield of 544 kg m−3 day−1 has been developed without using any modulating agents. This material also demonstrates enduring separation performance for multiple cycles, maintaining its efficacy after exposure to water or air for three months. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon nanofibrous membranes were prepared for adsorptive separation of VOCs. • The membranes showed hierarchical porous structures and functional surfaces. • The membranes possessed comparable adsorption quantities and fast kinetics. • The membranes exhibited good reusability and dynamic adsorption performance. Volatile organic compounds (VOCs) in the air pose great health risks to humans and the environment. Adsorptive separation technology has proven effective in mitigating VOC pollution, with the adsorbent being the critical component. Therefore, the development of highly efficient adsorbent materials is crucial. Carbon nanofibers, known for their physical–chemical stability and rapid adsorption kinetics, are promising candidates for removing VOCs from the air. However, the relatively simple porous structures and inert surface chemical properties of traditional carbon nanofibers present challenges in further enhancing their application performance further. Herein, a hierarchical porous carbon nanofibrous membrane was prepared using electrospinning technology and a one-step carbonization & activation method. Phenolic resin and polyacrylonitrile were used as co-precursors, with silica nanoparticles serving as the dopant. The resulting membrane exhibited a specific surface area of up to 1560.83 m2/g and surfaces rich in functional O-/N- groups. With a synergistic effect of developed micro- and meso -pores and active chemical surfaces, the carbon nanofibrous membrane demonstrated excellent adsorption separation performance for various VOCs, with comparable adsorption capacities and fast kinetics. Moreover, the membrane displayed remarkable reusability and dynamic adsorption performance for different VOCs, indicating its potential for practical applications. [ABSTRACT FROM AUTHOR]

Adsorptive separation of Gd3+ ions was evaluated using DOWEX-50×8 ion exchange resin. It has shown a maximum adsorption capacity of 228.50 mg/g at optimum pH 5 and room temperature. Separation of Gd isotopes was investigated using packed bed columns of the resin in displacement chromatographic techniques where 1,2-cyclohexanedinitrilotetraacetic acid was used as displacer in the mobile phase. Isotopic analysis data by using MC‒ICP‒MS confirmed that the front end of the Gd adsorption band exhibited enrichment of the heavier isotope (160Gd), while the lighter isotopes (157Gd and 155Gd) were concentrated at the rear end of the stationary phase. [ABSTRACT FROM AUTHOR]

Targeted sorbents for the real-world adsorptive separation of heavy metals shall exhibit high sorption capacity, reusability, and cost-effectiveness. In this study, a novel composite sorbent has been synthesized for the concurrent mitigation of iron, lead, and zinc metal ions from synthetic wastewater systems. For this purpose, chitosan with alternate molecular weight (low, medium, and high) and with hydroxyl and amine functional groups was employed as a substrate. The successful anchoring of the organic compound citric acid was achieved with the glutaraldehyde crosslinker. The medium molecular weight chitosan-citric acid (medium Cit-CS) has been evaluated to achieve optimal metal uptake of 243.90, 3.93, and 144.93 mg g−1 for zinc, lead, and iron from intricate Zn dominant adsorbate system. Accordingly, it was ascertained that other alternative ions in the adsorbate system significantly alter the sorption patterns. The validation of the chemisorption process was effectively established through the consistency observed in the pattern of adsorption as well as the successful modeling via the pseudo-second-order (PSO) approach. Following this, the desorption of metal ions was effective with simple basic and acidic eluents and for a three-cycle-based simultaneous regeneration. In summary, the findings demonstrate the promising performance of the sorbent for metal ions eradication from intricate solutions. [ABSTRACT FROM AUTHOR]

The global increasing contamination of water resources with toxic metals such as copper (Cu), poses severe threats to human health and aqueous ecosystems. Therefore, the ultrafiltration mixed matrix membranes (UF MMMs) possess an applicable approach for the removal of copper ions. This novel fabricated technology can be applied in various wastewater treatment systems for the removal of heavy metals, especially copper. MMMs were fabricated by blending polysulfone (Psf) with additives into the dope solution via the phase inversion method by incorporating titanium dioxide (TiO2) and polyethylene glycol (PEG) in Psf MMMs. Seven Psf MMMs samples labelled M0 to M6, each with its own formulation, were prepared and tested for density, porosity, and degree of Cu retention. MMMs were further characterized via Fourier transform infrared spectroscopy (FTIR), which revealed the range of the IR spectrum of Psf polymer membrane from 1319 cm-1 to 1600 cm-1, 1650 cm-1 to 3400 cm-1 for PEG, and 800 cm-1 to 3600 cm-1 for TiO2 NPs. As for the scanning electron microscopy (SEM), M6 (Psf/TiO2/PEG 6000) was found to be the most dense and highest porous morphology asymmetric Psf MMM. The retained percentage of Cu and flux for M6 attained the highest value of 80.3% and 136.99 L/m2.h respectively, whereas for the neat Psf membrane, M0 exhibited the lowest retained percentage of Cu and flux, about 25.8% and 61.64 L/m2.h. The inclusion of pore former and additives has shown an improvement of 54.5% in the copper rejection. Moreover, M6 displayed the highest antifouling properties compared to other Psf MMMSs. This study proves that PEG and TiO2 additives have significant potential to improve membrane performance due to the highest percentage of Cu retained on the surface of the membrane as adsorptive separation on Psf MMMs. [ABSTRACT FROM AUTHOR]

This research endeavour aims to investigate the adsorptive separation of the branched chain (BCAA) and aromatic amino acids (AAA). Based on the different molecular sizes of BCAA and AAA, zeolitic imidazolate frameworks (ZIFs) with different pore structures were prepared by regulating the size of imidazole ligands. The structure and pore shape were characterized by Fourier transform infrared spectroscopy (FT‐IR), x‐ray diffraction (XRD), scanning electron microscope (SEM), and BET surface area (BET). The results indicated the successful synthesis of ZIF‐[Co(mIm)2], ZIF‐[Co(eIm)2], and ZIF‐[Co(pIm)2] with pore size distribution of 7.821, 6.943, and 9.394 Å, and particle size of these ZIFs was approximately 4 μm. ZIF‐[Co(eIm)2] was chosen as the optimal ZIFs for the separation of BCAA and AAA. The adsorption experiment was evaluated in the respective single and binary systems. The corresponding data in a single system demonstrated that ZIF‐[Co(eIm)2] showed good adsorption performance for BCAA and poor for AAA. Furthermore, the adsorption behaviour under experimental conditions conformed well to the pseudo‐second‐order kinetic model and Langmuir isotherm. ZIF‐[Co(eIm)2] had great separation ability for BCAA/AAA in their binary system. Finally, regeneration studies further manifested that ZIF‐[Co(eIm)2] exhibited fine reusability performance with adsorption efficiencies still higher than 70% after five cycles. This study exhibits a novel path for the design of adsorbents for efficient separation of BCAA/AAA. [ABSTRACT FROM AUTHOR]

In this work, the phase inversion approach is used to synthesize a blended mixed matrix membrane from cellulose acetate polymer and sugarcane bagasse biochar. The experiments were carried out to estimate the extent of chlorpyrifos (CPS) pesticide removal. The results showed that the removal rate was more than 99% in making the filtered water suitable enough for domestic use. The physical and functional characteristics of the membranes, such as permeability, and contact angle were identified. The changes in the membrane characteristics were observed using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction both before and after the experimental trials. Experiments were conducted to assess not only the rejection characteristics of CPS, as a function feed concentration, but also the effect co-ions on the rejection used to analyze the composition both before and after filtration. The effects of initial CPS concentration, biochar loading, and co-ions on the membrane were investigated. The membranes showed contact angles between 70° and 97° and a permeability between 0.25 × 1010 m Pa−1 s−1 and 0.31 × 1010 m Pa−1 s−1. The effective removal of CPS from the contaminated aqueous stream was attributed to a combination of adsorptive uptake and membrane-based separation. CPS was found to get adsorbed onto the membrane matrix through an intraparticle diffusion mechanism along with an irreversible monolayer adsorption. The membrane-solute adsorptive interaction was represented by Langmuir isotherm and intraparticle diffusion models with a maximum adsorption capacity of 192.3 mg g−1. The findings indicated the efficacy of biochar-cellulose acetate mixed matrix membrane for sustainable and eco-friendly treatment of chlorpyrifos contaminated water. [ABSTRACT FROM AUTHOR]

For industrial tail gas to be converted into high-purity hydrogen, the H2-N2 mixture needs to be separated efficiently. This work examined the adsorption characteristics and competitive mechanisms of H2 and N2 on LTA- and FAU-type zeolites, at 77 K, 298 K, and 0.1–10 bar by thoroughly analyzing results of adsorption capacity experiments and molecular simulations. In the Grand Canonical Monte Carlo (GCMC) simulations, the force field causing a molecular dipole of H2 and the polarization force field of N2 are first applied. The accuracy of the force field was experimentally verified. The findings indicate that N2 and H2 loading on Ca-FAU (Ca-LTA) are higher than Na-FAU (Na-LTA). On NaX at 77 K, the highest adsorption selectivity (N2/H2) is observed; on NaA at 298 K, it is the opposite. The GCMC data findings demonstrate that H2 and N2 have remarkably similar adsorption sites, with framework oxygen atoms and non-framework cations serving as the main adsorption sites for adsorbate molecules. Furthermore, the rate at which H2 diffuses is higher than that of N2. The study of redistribution charge before and after adsorption demonstrated that N2 has a greater affinity for the framework oxygen atoms than H2. This study provides a molecular theoretical foundation for the adsorption behavior of H2-N2 mixture in zeolites. [ABSTRACT FROM AUTHOR]

Performance analysis of the adsorptive separation of ethylene downstream of an oxidative coupling of methane (OCM) process, being an alternative process for converting methane content of natural gas or other methane-rich sources to ethylene, was studied in this research for a production capacity of 1 Mt/yr. This was motivated by observing promising adsorption characteristics and efficiency in the selective adsorption of ethylene using 13X zeolite-based sorbent. The energy and economic performance of alternative scenarios for retrofitting the adsorption unit into an integrated OCM process were analyzed. Simulations of the integrated OCM process scenarios include OCM unit, CO2-hydrogenation, ethane dehydrogenation and methane reforming sections. The use of efficient ethylene adsorption separation enabled the improvement of the economic and energy efficiency of the integrated OCM process under specific operating conditions. For instance, the invested amount of energy and the associated energy cost per ton of ethylene in the cryogenic ethylene-purification section of the integrated process using adsorption unit are, respectively, 75% and 89% lower than the reference integrated OCM process. Under the conditions considered in this analysis, the return on investment for the final proposed integrated OCM process structure using adsorption separation was found to be less than 9 years, and the potential for further improvement was also discussed. [ABSTRACT FROM AUTHOR]

Separating acetylene from carbon dioxide is important but highly challenging due to their similar molecular shapes and physical properties. Adsorptive separation of carbon dioxide from acetylene can directly produce pure acetylene but is hardly realized because of relatively polarizable acetylene binds more strongly. Here, we reverse the CO2 and C2H2 separation by adjusting the pore structures in two isoreticular ultramicroporous metal–organic frameworks (MOFs). Under ambient conditions, copper isonicotinate (Cu(ina)2), with relatively large pore channels shows C2H2‐selective adsorption with a C2H2/CO2 selectivity of 3.4, whereas its smaller‐pore analogue, copper quinoline‐5‐carboxylate (Cu(Qc)2) shows an inverse CO2/C2H2 selectivity of 5.6. Cu(Qc)2 shows compact pore space that well matches the optimal orientation of CO2 but is not compatible for C2H2. Neutron powder diffraction experiments confirmed that CO2 molecules adopt preferential orientation along the pore channels during adsorption binding, whereas C2H2 molecules bind in an opposite fashion with distorted configurations due to their opposite quadrupole moments. Dynamic breakthrough experiments have validated the separation performance of Cu(Qc)2 for CO2/C2H2 separation. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) that exhibit dynamic phase‐transition behavior under external stimuli could have great potential in adsorptive separations. Here we report on a zinc‐based microporous MOF (JNU‐80) and its reversible transformation between two crystalline phases: large pore (JNU‐80‐LP) and narrow pore (JNU‐80‐NP). Specifically, JNU‐80‐LP can undergo a dehydration‐induced cluster consolidation under heat treatment, resulting in JNU‐80‐NP with a reduced channel that allows exclusion of di‐branched hexane isomers while high adsorption of linear and mono‐branched hexane isomers. We further demonstrate the fabrication of MOF‐polymer composite (JNU‐80‐NP‐block) and its application in the purification of di‐branched isomers from liquid‐phase hexane mixtures (98 % di‐branched) at room temperature, affording the di‐branched hexane isomers with 99.5 % purity and close to 90 % recovery rate over ten cycles. This work illustrates an interesting dehydration‐induced cluster consolidation in MOF structure and the ensuing channel shrinkage for sieving di‐branched hexane isomers, which may have important implications for the development of MOFs with dynamic behavior and their potential applications in non‐thermal driven separation technologies. [ABSTRACT FROM AUTHOR]

In this work, the effect of amine groups of MOFs materials on the NO separation selectivity under the simulated mixed atmosphere had been first investigated by comparison of NO adsorptive separation selectivity of Fe‐BDC, Al‐BDC, FeAl‐BDC and Fe‐BDC‐NH2, Al‐BDC‐NH2, FeAl‐BDC‐NH2 synthesized by solvothermal method. The experimental results showed that the adsorption capacity of NO by Fe‐BDC‐NH2, Al‐BDC‐NH2, and FeAl‐BDC‐NH2 was significantly larger than Fe‐BDC, Al‐BDC, and FeAl‐BDC at 100 kPa, which indicated ‐NH2 promotes the adsorption of NO and was much higher than the adsorption capacity of CO2, O2, and N2 under the same conditions. The NO adsorption capacity and selectivity of bimetallic FeAl‐BDC‐NH2 were significantly better than that of monometallic Fe‐BDC‐NH2 and Al‐BDC‐NH2. The NO adsorption capacity of FeAl‐BDC‐NH2 can reach 216.42 cc g−1, which exceeded lots of MOFs materials reported, and the adsorption selectivities of NO/CO2 and NO/O2 by IAST under the simulated mixed atmosphere reached 1,350 and 15,962. It also proved that the material adsorbed NO because NO forms NONOate with ‐NH2 by the in situ IR and enthalpy calculation of adsorption, and the adsorption mechanism of NO was preliminarily investigated. The results provided a new direction for the application of adsorption and separation of NO in flue gas. [ABSTRACT FROM AUTHOR]

The MOF‐5@clinoptilolite (MOF@CP) composites are successfully synthesized using polyvinylpyrrolidone (PVP) for adsorption separation of CO2/CH4, CO2/N2, and CH4/N2. The effects of the PVP amounts on the dispersity of MOF‐5 on CP random lamellas of the MOF@CPs are evaluated via various characterizations. Meanwhile, their single‐component gas adsorption isotherms, breakthrough experiments, and cycling test are measured. The results elucidate that the used PVP amount has a significant influence on the particle size and the uniformity of MOF‐5 dispersed on CP random lamellas. The MOF‐5‐loaded amount in MOF@CP is estimated to be up to 42.52 wt.%. Especially, the surface fractal evolutions indicated the surfaces of MOF@CP became from rough to smooth with the increase of PVP. The CO2/CH4, CO2/N2, and CH4/N2 selectivity factors of MOF@CP are higher than that of CP, displaying a better separation performance. Their cycling test revealed that MOF@CPs could be used repetitively, highlighting efficiency for CO2 and CH4 separation. Meanwhile, the MOF‐5@CP stability under moisture is preliminarily investigated, showing higher moisture resistance stability than MOF‐5. Additionally, the grand canonical Monte Carlo simulations demonstrated the adsorption separation mechanism of the prepared MOF@CPs. [ABSTRACT FROM AUTHOR]

One of the key environmental problems underlying climate change and global warming is the persistent increase in atmospheric carbon dioxide concentration. Carbon capture and storage (CCS) systems can be based on, among others, solid porous sorbents (e.g., zeolites). A promising alternative to traditionally used sorbents may be appropriately structured hybrid adsorbents. With the proper geometry and synergistic combination of the sorbent with another material, e.g., a catalyst or a substance with certain useful physical features, they can gain new properties. The present study examined the dynamics of CO2 sorption in core–shell particles and, as a reference, in particles with a uniform structure. It was assumed that the sorbent (zeolite 5A) incorporated in a single particle had the form of microcrystals, which implies a bidisperse particle structure. As a second particle-forming material, a nickel catalyst (behaving as an inert) was adopted. The computational results confirmed that particle structure can provide an additional design parameter for adsorption columns and adsorptive reactors. The sorption-inactive shell proved to play a protective role when thermal waves moved through the bed. In addition, an important element determining sorption dynamics in core–shell particles was revealed to be the structure (e.g., mean pore diameter) controlling intraparticle mass transport. [ABSTRACT FROM AUTHOR]

Separation of the mixture of ethylene (C2H4) and ethane (C2H6) to produce polymer-grade C2H4 is of prime importance in the petrochemical industry. In this context, metal–organic frameworks (MOFs) featuring tunable pore metrics and surface chemistry, especially those with inverse C2H6/C2H4 adsorption selectivity, hold great promise in energy-effective purification of C2H4 by adsorptive separation, but often encounter the well-known trade-off between adsorption selectivity and capacity. In this work, we report two new MOFs by deploying the pore-space-partition (PSP) strategy for the purpose of reducing the pore aperture size while retaining the gas-accessible pore volume. As a result, Ni-bodc-tpt (bodc = bicyclo[2.2.2]octane-1,4-dicarboxylic acid, tpt = 2,4,6-tri(4-pyridyl)-1,3,5-triazine) by combining optimal pore size, large cage pore volume, and rich C–H binding sites exhibits concurrently high C2H6 adsorption capacity (131.65 cm3 g−1) and C2H6/C2H4 selectivity (1.8) at 298 K and 1 bar, which is superior or comparable to many benchmark C2H6-selective MOFs. A dynamic breakthrough experiment demonstrates that high-purity C2H4 (>99.9%) can be harvested in one step from a binary mixture of C2H6/C2H4 (50/50, v/v), attesting to the feasibility of this new MOF as a prospective C2H4 purification agent. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have shown promise for adsorptive separations of metal ions. Herein, MOFs based on highly stable Zr(IV) building units were systematically functionalized with targeted metal binding groups. Through competitive adsorption studies, it was shown that the selectivity for different metal ions was directly tunable through functional group chemistry. [ABSTRACT FROM AUTHOR]

Biobutanol stands out as an advanced renewable biofuel, yet its production through fermentation yields a low butanol concentration, necessitating expensive and energy-intensive separation methods, particularly by distillation. Alternative approaches, including adsorptive separation, have emerged, with the 2-column zeolite-based process showing promise. This study employed Aspen Plus for simulating adsorptive separation, utilized Pinch technology for heat integration, and analyzed various alternatives using the life cycle assessment (LCA) approach. Compared to the base case, which relied on our previously acquired experimental data and further purification through atmospheric distillation, the adoption of indirect heating/cooling adsorption reduced heating energy demand by 59.5%. Additionally, cooling energy usage was increased notably by 68.9%, and chilling prerequisites were eliminated. The implementation of Pinch technology further reduced heating and cooling energy requirements by approximately 36%. Multi-pressure distillation was also explored, revealing its potential to reduce heating energy consumption by 46.6%, accompanied by a modest 6.2% increase in cooling energy demand. A gate-to-gate LCA framework was used to evaluate the environmental impacts. The results showed that the combination of indirect heating/cooling adsorption, multi-pressure distillation, and energy-efficient practices resulted in over a 98% reduction in damages related to human health, ecosystem well-being, and resource depletion compared to the base case. Prioritization of key performance indicators revealed that human health had the most significant influence, with prominent midpoint effects attributed to human toxicity and global warming. This study underscores the pivotal role of energy targeting in curtailing energy consumption and enhancing the sustainability of adsorptive biobutanol separation.

Adsorptive separation of propyne/propylene (C3H4/C3H6) is a crucial yet complex process, however, it remains a great difficulty in developing porous materials that can meet the requirements for practical applications, particularly with an exceptional ability to bind and store trace amounts of C3H4. Functionalization of pore‐partitioned metal–organic frameworks (ppMOFs) is methodically suited for this challenge owing to the possibility of dramatically increasing binding sites on highly porous and confined domains. We here immobilized Lewis‐basic (−NH2) and Lewis‐acidic (−NO2) sites on this platform. Along with an integrated nature of high uptake of C3H4 at 1 kPa, high uptake difference of C3H4−C3H6, moderated binding strength, promoted kinetic selectivity, trapping effect and high stability, the NH2‐decorated ppMOF (NTU‐100‐NH2) can efficiently produce polymer‐grade C3H6 (99.95 %, 8.3 mmol ⋅ g−1) at room temperature, which is six times more than the NO2‐decorated crystal (NTU‐100‐NO2). The in situ infrared spectroscopy, crystallographic analysis, and sequential blowing tests showed that the densely packed amino group in this highly porous system has a unique ability to recognize and stabilize C3H4 molecules. Moving forward, the strategy of organic functionalization can be extended to other porous systems, making it a powerful tool to customize advanced materials for challenging tasks. [ABSTRACT FROM AUTHOR]

The effective and affordable separation of oil and water, a crucial process in the safe handling of environmental disasters such as crude oil spills and recovery of valuable resources, is a highly sought-after yet challenging task. Herein, superhydrophobic PU sponge was fabricated for the fast and cost-effective adsorptive separation of oil and different organic solvents from water. Octadecyltrichlorosilane (OTS)-functionalized Fe 3 O 4 @SiO 2 core–shell microspheres were dip-coated on the surface of porous materials via a dip-coating process, thereby endowing them with superhydrophobicity. Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores, the resulting superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil–water mixtures, including oil–water suspensions and emulsions. Remarkably, after the recovery of the adsorbed oil via mechanical extrusion, these superhydrophobic materials could be reused multiple times and maintain their oil–water separation efficacy even after 10 oil–water separation cycles. [ABSTRACT FROM AUTHOR]

One‐step separation of C2H4 from ternary gas mixtures containing acetylene (C2H2), ethylene (C2H4), and carbon dioxide (CO2) represents a great challenge in chemical industry. Herein, we report the electro‐field alignment in a novel anion‐pillared MOF (SIFSIX‐TEPE‐Cu) for benchmark C2H4 separation from C2H2/CO2/C2H4 gas mixtures. The semi‐cage cavities featuring capped facets generated negative potentials along anion pillars and compensatory positive‐charged electro‐fields along organic ligands (TEPE) that facilitate specific recognitions of C2H2 and CO2 over C2H4. As a result, SIFSIX‐TEPE‐Cu exhibits high adsorption capacities for C2H2 (123 cm3 g−1) and CO2 (65 cm3 g−1) at 1.0 bar and 298 K. Notably, the record‐high C2H2 uptake (78 cm3 g−1) at 0.01 bar and remarkable C2H2/C2H4 selectivity (615.2) renders benchmark trace C2H2 removal ability. Dynamic breakthrough experiments demonstrate the benchmark productivity for high‐purity C2H4 (>99.995%) of 194.7 mol kg−1 and 5.96 mol kg−1 from binary C2H2/C2H4 (1/99, v/v) and ternary C2H2/CO2/C2H4 (1/9/90, v/v/v) gas mixtures. [ABSTRACT FROM AUTHOR]

Hydrofluorocarbons (HFCs) have important applications in different industries; however, they are environmentally unfriendly due to their high global warming potential (GWP). Hence, reclamation of used hydrofluorocarbons via energy-efficient adsorption-based separation will greatly contribute to reducing their impact on the environment. In particular, the separation of azeotropic refrigerants remains challenging, such as typical mixtures of CH2F2 (HFC-23) and CHF3 (HFC-32), due to a lack of adsorptive mechanisms. Metal–organic frameworks (MOFs) can provide a promising solution for the separation of CHF3–CH2F2 mixtures. In this study, the adsorption mechanism of CHF3–CH2F2 mixtures in TIFSIX-2-Cu-i was revealed at the microscopic level by combining static pure-component adsorption experiments, molecular simulations, and density-functional theory (DFT) calculations. The adsorption separation selectivity of CH2F2/CHF3 in TIFSIX-2-Cu-i is 3.17 at 3 bar under 308 K. The existence of similar TiF62− binding sites for CH2F2 or CHF3 was revealed in TIFSIX-2-Cu-i. Interactions between the fluorine atom of the framework and the hydrogen atom of the guest molecule were found to be responsible for determining the high adsorption separation selectivity of CH2F2/CHF3. This exploration is important for the design of highly selective adsorbents for the separation of azeotropic refrigerants. [ABSTRACT FROM AUTHOR]

Double-cavity Q[n]s are relatively new members of the Q[n] family and have garnered significant interest due to their distinctive structures and novel properties. While they incorporate n glycoluril units, akin to their single-cavity counterparts, their geometry can best be described as resembling a figure-of-eight or a handcuff, distinguishing them from single-cavity Q[n]s. Despite retaining the core molecular recognition traits of single-cavity Q[n]s, these double-cavity variants introduce fascinating new attributes rooted in their distinct configurations. This overview delves into the synthesis, structural attributes, properties, and intriguing applications of double-cavity Q[n]s. Some of the applications explored include their role in supramolecular polymers, molecular machinery, supra-amphiphiles, sensors, artificial lightharvesting systems, and adsorptive separation materials. Upon concluding this review, we discuss potential challenges and avenues for future development and offer valuable insights for other scholars working in this area with the aim of stimulating further exploration and interest. [ABSTRACT FROM AUTHOR]

Pure and composite Cu-Amino-terephthalate MOF has been produced by ultrasound wave to evaluate the adsorption capacity and adsorptive separation of D 2 and H 2 at 77 K up to 1000 mbar. The frameworks are characterized by XRD, SEM, FTIR, ICP, BET, and EDX analysis. Separation studies were performed using idealized adsorption solution theory (IAST) and direct measurements. Isotherm studies showed the data had good agreement with the Langmuir model and the adsorption capacity of deuterium was greater than hydrogen in all samples. Linear Driving Force (LDF) model was applied to investigate the effective diffusion coefficients of deuterium and hydrogen in the frameworks. The LDF model showed hydrogen molecules diffused faster than deuterium molecules in all frameworks. In the adsorption enthalpy studies, there was a slight difference between deuterium and hydrogen adsorption energy. In this regard, Cu-BDC-NH 2 @rGO showed a higher adsorption enthalpy difference compared to Cu-BDC-NH 2. Finally, the D 2 /H 2 selectivity of the composite framework was greater than the pure one. Regarding this matter, the Cu-BDC-NH 2 @rGO MOF showed a maximum selectivity factor of about 2.2 at 77 K and 1000 mbar based on the IAST model. • Preparation and characterization of pure and composite Cu-BDC-NH 2 MOFs. • Explore the effect of graphene content on hydrogen isotope separation. • Investigating the kinetic behavior of hydrogen isotopes in adsorption process. • Investigating the effect of graphene content on hydrogen and deuterium adsorption capacity. [ABSTRACT FROM AUTHOR]

Nanostructured zeolite 13X, synthesized from basalt rock via alkali fusion and hydrothermal procedures, demonstrates excellent adsorption performance for light gases (CO2, CH4, N2, and H2). Its robust CO2 separation properties, evident in the adsorption capacity and selectivity order (CO2 >> CH4 > N2 >> H2). The measured adsorption isotherms fit well with the Sips equation, and heterogeneous adsorption behaviors correlate with the isosteric heat of adsorption and adsorption energy distribution. Predicted selectivities via ideal adsorbed solution theory range from 990 to 1,415 (CO2/H2), 244–360 (CO2/N2), and 135–254 (CO2/CH4), indicating significant potential for adsorptive CO2 separation. Natural-basalt-originated, nanostructured zeolite has been created for strong and selective gas adsorption characteristics useful for engineering applications including energy source creation and environmental cleaning, with the selectivity strongly correlated with polarizability. [ABSTRACT FROM AUTHOR]

Purifying olefin from ternary paraffin/olefin/alkyne mixtures through a one‐step adsorption process is extremely desirable. Herein, a stable zirconium(IV) metal‐organic framework with a customized pore surface composed of nonpolar phenyl and slightly polar thiophene rings is reported to access the adsorption preference of paraffin and alkyne over olefin. Noteworthily, this material displays a superior ability to discriminate C3 hydrocarbon molecules, which is principally more challenging compared with C2 ones and rarely documented. Computational studies disclose that its featured pore shape fits well with C3 gas molecules, enabling them to get close contact with the immobilized affinity sites. Leveraging surface chemistry and pore shape engineering synergistically gives rise to excellent C3 adsorption capacities (>5 mmol g−1) and concurrently high C3H8/C3H6 (1.4) and C3H4/C3H6 (1.9) selectivities (at 298 K and 1 atm). Dynamic column breakthrough experiments demonstrate that one‐step purification of C2H4 and C3H6 can be simultaneously realized on this material. [ABSTRACT FROM AUTHOR]

Biobutanol stands out as an advanced renewable biofuel, yet its production through fermentation yields a low butanol concentration, necessitating expensive and energy-intensive separation methods, particularly by distillation. Alternative approaches, including adsorptive separation, have emerged, with the 2-column zeolite-based process showing promise. This study employed Aspen Plus for simulating adsorptive separation, utilized Pinch technology for heat integration, and analyzed various alternatives using the life cycle assessment (LCA) approach. Compared to the base case, which relied on our previously acquired experimental data and further purification through atmospheric distillation, the adoption of indirect heating/cooling adsorption reduced heating energy demand by 59.5%. Additionally, cooling energy usage was increased notably by 68.9%, and chilling prerequisites were eliminated. The implementation of Pinch technology further reduced heating and cooling energy requirements by approximately 36%. Multi-pressure distillation was also explored, revealing its potential to reduce heating energy consumption by 46.6%, accompanied by a modest 6.2% increase in cooling energy demand. A gate-to-gate LCA framework was used to evaluate the environmental impacts. The results showed that the combination of indirect heating/cooling adsorption, multi-pressure distillation, and energy-efficient practices resulted in over a 98% reduction in damages related to human health, ecosystem well-being, and resource depletion compared to the base case. Prioritization of key performance indicators revealed that human health had the most significant influence, with prominent midpoint effects attributed to human toxicity and global warming. This study underscores the pivotal role of energy targeting in curtailing energy consumption and enhancing the sustainability of adsorptive biobutanol separation. [ABSTRACT FROM AUTHOR]

Multiple impurities removal represents one of the most daunting challenges in gas purification, but the attainment of efficient adsorptive separation is hindered by the difficulty in designing adsorbents that could simultaneously capture different impurities. Herein, we revealed a molecular trap within Zn‐trz‐ox (trz = 1,2,4‐triazole; ox = oxalic acid) that featured positive H and negative O sites, and the suitable pore size, which exhibited remarkable one‐step C2H4 purification performance directly from quaternary C2H4/C2H2/C2H6/CO2 mixtures. The separation selectivities of C2H4 with respect to CO2, C2H2, and C2H6 are 9.8, 2.6, and 2.5, higher than the sole adsorbent yet reported. Meanwhile, polymer grade C2H4 (≥99.95%) could be directly obtained with record C2H4 productivity of 1.5 mol kg−1, over 10 times higher than that of the previous benchmark material. The deep insight into the binding behavior revealed by simulation studies offers important clues for the design of advanced adsorbent for multiple impurities capture. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The separation of C2H4 from C2H6/C2H4 mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework (MOF) BUT-315-a as a C2H6-selective adsorbent for the separation of C2H6/C2H4 gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C2H6 uptake of 97.5 cm3 g−1, giving superior high separation potential ΔQ (2226 mmol L−1) for equimolar C2H6/C2H4 at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C2H6 and the framework. This work highlights a new benchmark material for C2H6/C2H4 separation and provides guidance for designing adsorbent for separation applications.

Global warming has become a growing concern over decades, prompting numerous research endeavours to reduce the carbon dioxide (CO2) emission, the major greenhouse gas (GHG). However, the contribution of other non-CO2 GHGs including methane (CH4), nitrous oxide (N2O), fluorocarbons, perfluorinated gases, etc. should not be overlooked, due to their high global warming potential and environmental hazards. In order to reduce the emission of non-CO2 GHGs, advanced separation technologies with high efficiency and low energy consumption such as adsorptive separation or membrane separation are highly desirable. Advanced porous materials (APMs) including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), porous organic polymers (POPs), etc. have been developed to boost the adsorptive and membrane separation, due to their tunable pore structure and surface functionality. This review summarizes the progress of APM adsorbents and membranes for non-CO2 GHG separation. The material design and fabrication strategies, along with the molecular-level separation mechanisms are discussed. Besides, the state-of-the-art separation performance and challenges of various APM materials towards each type of non-CO2 GHG are analyzed, offering insightful guidance for future research. Moreover, practical industrial challenges and opportunities from the aspect of engineering are also discussed, to facilitate the industrial implementation of APMs for non-CO2 GHG separation. [ABSTRACT FROM AUTHOR]

The combination of macrocyclic chemistry with co-crystal engineering has promoted the development of materials with vapochromic behaviors in supramolecular science. Herein, we develop a macrocycle co-crystal based on hybrid[4]arene and 1,2,4,5-tetracyanobenzene that is able to construct vapochromic materials. After the capture of benzene and toluene vapors, activated hybrid[4]arene-based co-crystal forms new structures, accompanied by color changes from brown to yellow. However, when hybrid[4]arene-based co-crystal captures cyclohexane and pyridine, neither structures nor colors change. Interestingly, hybrid[4]arene-based co-crystal can separate benzene from a benzene/cyclohexane equal-volume mixture and allow toluene to be removed from a toluene/ pyridine equal-volume mixture with purities reaching 100%. In addition, the process of adsorptive separation can be visually monitored. The selectivity of benzene from a benzene/cyclohexane equal-volume mixture and toluene from a toluene/ pyridine equal-volume mixture is attributed to the different changes in the charge-transfer interaction between hybrid[4]arene and 1,2,4,5-tetracyanobenzene when hybrid[4]arene-based co-crystal captures different vapors. Moreover, hybrid[4]arene-based co-crystal can be reused without losing selectivity and performance. This work constructs a vapochromic material for hydrocarbon separation. Cocrystal engineering combined with macrocycle chemistry has allowed the development of materials with vapochromic characteristics. Here, the authors report the development of a macrocycle cocrystal for the separation of trace solvents. [ABSTRACT FROM AUTHOR]

The shape and topology of pores have significant impacts on the gas storage properties of nanoporous materials. Metal–organic frameworks (MOFs) are ideal materials with which to tailor to the needs of specific applications, due to properties such as their tunable structure and high specific surface area. It is, therefore, particularly important to develop descriptors that accurately identify the topological features of MOF pores. In this work, a topological data analysis method was used to develop a topological descriptor, based on the pore topology, which was combined with the Extreme Gradient Boosting (XGBoost) algorithm to predict the adsorption performance of MOFs for methane/ethane/propane. The final results show that this descriptor can accurately predict the performance of MOFs, and the introduction of the topological descriptor also significantly improves the accuracy of the model, resulting in an increase of up to 17.55% in the R2 value of the model and a decrease of up to 46.1% in the RMSE, compared to commonly used models that are based on the structural descriptor. The results of this study contribute to a deeper understanding of the relationship between the performance and structure of MOFs and provide useful guidelines and strategies for the design of high-performance separation materials. [ABSTRACT FROM AUTHOR]