An anionic 3D MOF featuring 9-connected Ni3(μ3-OH) secondary building units (SBUs), (Me2NH2)2[Ni6(OH)2(Bpdc)3(4-Ptz)6]·11H2O (NJTU-Bai90; NJTU-Bai denotes Nanjing Tech University Bai’s group), was hydrothermally synthesized using the bifunctional ligands bicyclo[1.1.1]pentane-1,3-dicarboxylic acid (H2Bpdc) and 4-(2H-tetrazol-5-yl)pyridine (4-HPtz). This MOF crystallizes in I-43 m space group and possesses intersecting 3D channels packed by trigonal-pyramidal and tetrahedral cages. Tailored for reversible C2H6 adsorption and one-step purification of polymer-grade C2H4, NJTU-Bai90 not only has a high BET surface area of 1465.7 m2 g−1 but also exhibits excellent stability in aqueous solutions at room temperature for at least one month. NJTU-Bai90 exhibits superior C2H6 uptake (97.6 cm3 g−1 at 298 K and 82.5 cm3 g−1 at 308 K, both measured at 1 bar) in comparison with C2H4 (85.5 cm3 g−1 at 298 K and 68.4 cm3 g−1 at 308 K, both measured at 1 bar). Remarkable IAST selectivity values (1.51 and 1.56, respectively) are maintained even at elevated temperatures. Furthermore, dynamic breakthrough experiments demonstrate that a C2H6/C2H4 mixture (1/15, v/v) can be efficiently separated in one step and that polymer-grade C2H4 yielding with a productivity of 19.1 mL g−1 at 298 K and 1 bar. The distinct retention times of C2H6 and C2H4 on NJTU-Bai90-packed separation columns further highlight the material’s great potential for industrial gas separation applications.

An anionic 3D MOF featuring 9-connected Ni3(mu 3-OH) secondary building units (SBUs), (Me2NH2)2[Ni6(OH)2(Bpdc)3(4-Ptz)6]& sdot;11H2O (NJTU-Bai90; NJTU-Bai denotes Nanjing Tech University Bai's group), was hydrothermally synthesized using the bifunctional ligands bicyclo[1.1.1]pentane-1,3-dicarboxylic acid (H2Bpdc) and 4-(2H-tetrazol-5-yl)pyridine (4-HPtz). This MOF crystallizes in I-43 m space group and possesses intersecting 3D channels packed by trigonal-pyramidal and tetrahedral cages. Tailored for reversible C2H6 adsorption and one-step purification of polymer-grade C2H4, NJTU-Bai90 not only has a high BET surface area of 1465.7 m2 g- 1 but also exhibits excellent stability in aqueous solutions at room temperature for at least one month. NJTU-Bai90 exhibits superior C2H6 uptake (97.6 cm3 g- 1 at 298 K and 82.5 cm3 g- 1 at 308 K, both measured at 1 bar) in comparison with C2H4 (85.5 cm3 g- 1 at 298 K and 68.4 cm3 g- 1 at 308 K, both measured at 1 bar). Remarkable IAST selectivity values (1.51 and 1.56, respectively) are maintained even at elevated temperatures. Furthermore, dynamic breakthrough experiments demonstrate that a C2H6/C2H4 mixture (1/15, v/v) can be efficiently separated in one step and that polymer-grade C2H4 yielding with a productivity of 19.1 mL g- 1 at 298 K and 1 bar. The distinct retention times of C2H6 and C2H4 on NJTU-Bai90-packed separation columns further highlight the material's great potential for industrial gas separation applications.

Natural deep eutectic solvents (NDESs) are recognized as promising membrane materials for sustainable SO2 separation. Evaluating their separation performances is necessary, as well as understanding of the role that each hydrogen bonding site (including anion and functional groups in NDESs) plays in SO2 separation. Herein, three choline chloride (ChCl)-based NDESs bearing different number and type of functional groups were firstly incorporated into Pebax matrix to fabricate blended membranes for removing SO2 from CO2 and N-2. The Pebax/NDES membranes show SO2 permeability up to 10502 Barrer (0.20 bar and 40 degrees C), with excellent SO2/N-2 and SO2/CO2 selectivity of 1808 and 62.5 obtained, respectively, which are enhanced by 156 %, 61.5 % and 56.1 % compared with those in neat Pebax membrane. By means of gas solubility and diffusivity measurements, quantum chemical calculations and spectral characterizations, the highly-reversible multi-site interactions between SO2 and hydrogen bonding sites in NDESs (Cl- center dot center dot center dot SO2, carbonyl O center dot center dot center dot SO2 and hydroxyl O center dot center dot center dot SO2) were revealed. Meanwhile, the strength of hydrogen bonding network inside the NDESs, which is governed by the hydrogen bonding sites, is found to significantly influence the gas diffusion. More importantly, SO2/CO2/N-2 (2.5/15/82.5 mol%) mixed gas separation experiment also displays the superior separation performance and long-term stability of Pebax/NDES membrane.

Metallic residues in biomass‐derived hard carbons (HCs) are conventionally considered detrimental to Na + ions storage, recent breakthroughs reveal that controlled metal‐ion doping can substantially enhance electrochemical performance. Suitable metal doping is beneficial to enhance its overall performance. Consequently, manipulating the microstructure of HCs at the molecular level to achieve adaptive doping with metal ions, thereby fostering smoother diffusion environments and increasing storage sites for Na + ions, is crucial for achieving exceptional sodium‐ion batteries (SIBs) performance. This review delves into the commercialization potential of SIBs and provides a comprehensive summary of the development trajectory of metal ion‐catalyzed hydrocarbons (MICHCs), which encompasses synthesis methodologies, the intricate relationship between metal doping position/content and performance, underlying reaction mechanisms. Regarding the catalytic mechanism of metal ions, this review outlines the interaction between metal ions and HCs, offering theoretical foundations and practical guidance for developing high‐performance sodium storage materials. By regulating the content and type of metal ions, one can adjust the physicochemical properties of the local microstructure and improve the electrochemical properties of MICHCs. Research on MICHCs not only advances related disciplines but also fosters technological innovation and industrial upgrading. This review discusses the future developments and challenges facing key technologies in this burgeoning field.

Recyclable chitosan-based ionic gel membranes containing carboxyl-functionalized ionic liquids were fabricated for separation of H 2 S.

Chitosan (CS) is a potential membrane material for acid gas separation owing to its advantages of low cost, high biocompatibility, good film-forming property, and abundant amine groups. However, due to the strong hydrogen bonding network inside bulky CS, it has poor solvent processability and high membrane crystallinity leading to slow gas permeation. Herein, via alkylating primary amine on chitosan using 1-bromohexyl-3-methylimidazo-lium bromide ([Brhmim]Br), water-processable ionic liquid-grafted chitosan (ICS) membrane was fabricated for H2S separation. Furthermore, polyethylene glycol (PEG) was introduced into ICS to improve H2S separation performance owing to its good plasticizing ability and highly reversible hydrogen bonding interaction with H2S. The successful fabrication of ICS and ICS/PEG membranes was validated using various characterizations. Notably, H2S/CO2/CH4 (20/20/60 vol%) mixed gas permeation test shows H2S permeability up to similar to 1100 Barrer, with desired H2S/CH4 (similar to 24) and H2S/CO2 (similar to 11) selectivity obtained. Quantum chemical calculations revealed that both the ionic liquid and PEG have highly reversible hydrogen bonding interaction with H2S, which facilitates H2S permeation. Overall, this work proposes a novel and green method for preparing modified chitosan membranes targeting H2S separation, which may provide a new insight into the design of sustainable membrane materials for natural gas desulfurization.

Removal of H2S and CO2 is a key step for natural gas upgrading. However, further separating H2S/CO2 remains challenging as they are both acid gas with similar kinetic diameters, incurring complex processes and high cost for recovering H2S as sulfur resource. Herein we reported for the first time the introduction of highly reversible hydrogen bonding into Pebax/deep eutectic solvent (DES) blended membranes comprising 1-ethyl-3-methylimidazolium chloride ([Emim]Cl)-based DESs for selectively separating H2S from CO2 and CH4. The successful fabrication of Pebax/DES membranes was confirmed by various characterizations. Benefitting from the highly reversible DES–H2S hydrogen bonding interaction, the H2S permeability, H2S/CO2 and H2S/CH4 selectivity for single gas tests are high up to 1829 Barrer, 14.35 and 242.0, respectively. Based on solution-diffusion data, the acidic [Emim]Cl/levulinic acid (Lev) DESs are found to be the most efficient owing to the moderate DES–H2S hydrogen bonding interaction and thus fast H2S diffusion, which was also confirmed by quantum chemical calculations coupled with visual study of weak interactions. Permeation test of mixed gas shows that Pebax/DES blended membranes can steadily and efficiently separate H2S/CO2/CH4 (3/3/94 vol.%) ternary gas, with 1450 Barrer of H2S permeability, 34.5 of H2S/CO2 selectivity and 160 of H2S/CH4 selectivity obtained, which may indicates the applicability of these materials in desufuration of natural gas. To summarize, this work demonstrated the vital role of DES–H2S hydrogen bonding interaction in dominating H2S permeation, which may provide an easy but effective way for fabricating high-performance H2S sepration membranes.

SO2 is a major atmospheric pollutant leading to acid rain and smog. As a new generation of green solvents, deep eutectic solvents (DESs) have been widely investigated for gas capture. Nevertheless, studies on DES-based membranes for SO2 separation are yet minimal. Herein, we devised polymer/DES blended membranes comprising 1-butyl-3-methyl-imidazolium bromide ([Bmim]Br)/diethylene glycol (DEG) DES and poly (vinylidene fluoride) (PVDF), and these membranes were firstly used for selective separation of SO2 from N2 and CO2. The permeability of SO2 reaches up to 17480 Barrer (0.20 bar, 40 ºC) in PVDF/DES blended membrane containing 50 wt% of [Bmim]Br/DEG (2:1), with ultrahigh SO2/N2 and SO2/CO2 selectivity of 3690 and 211 obtained, respectively, far exceeding those in the state-of-the-art membranes reported in literature. The highly-reversible multi-site interaction between SO2 and [Bmim]Br/DEG DES was revealed by spectroscopic analysis. Furthermore, the PVDF/DES blended membrane was also able to efficiently and stably separate SO2/CO2/N2 (2.5/15/82.5%) mixed gas for at least 100 h. This work demonstrates for the first time that [Bmim]Br-based DESs are very efficient media for membrane separation of SO2. The easy preparation, low cost and high performance enable polymer/DES blended membranes to be promising candidates for flue gas desulfurization.

The efficient and selective functionalization of icosahedral carboranes (C2B10H12) at the boron vertexes is a long-standing challenge owing to the presence of 10 inert B-H bonds in a similar chemical environment. Herein, we report a new reaction paradigm for direct B-H functionalization of icosahedral carboranes via B-H homolysis enabled by a nitrogen-centered radical-mediated hydrogen atom transfer (HAT) strategy. Both the HAT process of the carborane B-H bond and the resulting boron-centered carboranyl radical intermediate have been confirmed experimentally. The reaction occurs at the most electron-rich boron vertex with the lowest B-H bond dissociation energy (BDE). Using this strategy, diverse carborane derivatization, including thiolation, selenation, alkynylation, alkenylation, cyanation, and halogenation, have been achieved in satisfactory yields under a photoinitiated condition in a metal-free and redox-neutral fashion. Moreover, the synthetic utility of the current protocol was also demonstrated by both the scale-up reaction and the construction of carborane-based functional molecules. Therefore, this methodology opens a radical pathway to carborane functionalization, which is distinct from the B-H heterolytic mechanism in the traditional strategies.

With the aim of lowering energy consumption for gas regeneration, rational design of absorbents with low absorption enthalpy changes while retaining good gas solubility is of both scientific and practical significance. Herein, we demonstrated that acidic protic ionic liquid (APIL)-based deep eutectic solvents (DESs), which comprise N-ethylimidazole hydrochloride ([EimH]Cl) and ethylene glycol (EG), were able to reversibly absorb SO2 with high solubility (11.60 mol kg(-1)) and SO2/CO2 selectivity (655) at 293.2 K and 101.3 kPa. Meanwhile, [EimH]Cl/EG DESs exhibit very low enthalpy changes (?H-r(m)) ranging from -27.1 to -25.6 kJ mol(-1), and thus ease of desorption at very mild temperature conditions (303.2 K) with desorption ratios up to 99.6%. Recycling experiments showed that no obvious loss in capacity was found after six absorption-desorption cycles, suggesting good regeneration performance of [EimH]Cl/EG DESs. Moreover, spectroscopic analysis revealed the charge-transfer interaction between [EimH]Cl/EG and SO2.

Helium (He) is commercially produced from natural gas by low-temperature condensation. The process is energy extensive because of the extremely low He concentration (<0.3%) and the operation at cryogenic temperature. Herein we demonstrated DD3R zeolite membrane was efficient to extract He from natural gas at atmosphere temperature. The membrane performance was evaluated in terms of temperature, pressure and molar fractions. The overall membrane performance was dominated by the diffusivity selectivity. The single He permeance and ideal He/CH4 selectivity were 5.8 x 10 (9) mol(.)m (2.)s Pa-1. (1) and 79 under a feed pressure of 1.3 MPa. Even though He concentration was as low as 0.22%, the He permeance and He/CH4 mixture selectivity were 3.0 x 10 (9) mol(.)m 2.s Pa-1. (1) and 44 at 0.7 MPa. During the longterm operation (similar to 130 h) the membrane performance was stable even the feed mixture containing 3.6% ethane as contaminations. The results approved the feasibility of DD3R zeolite membranes for He extraction from natural gas. (c) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Hydrogen (H-2) is the most promising alternative to fossil energy for zero-emission of CO2. However, the by produced H-2 from coking process was generally burned as fuel. It is highly desired to recycle the H-2 from coke oven gas as the clean energy resource. Herein all-silica STT zeolite membranes were prepared from the fluorine-free precursor for H-2/CH4 separation. The crystallization period was shortened by 75% at the elevated temperature. After hydrothermal synthesis of 2 days, the membrane showed H-2 permeance up to 2.8 x 10(-8) mol.m(-2).s(-1).Pa-1 and H-2/CH4 selectivity up to 49.6 at 0.2 MPa and 298 K. More importantly, STT zeolite membrane was resistant to CO and H2S, which should be prevented from feeding to the commercial polymeric and Pd membranes. The membrane was stable up to 336 h in the simulated coke oven gas of 63 H-2: 28 CH4: 7 CO: 2 C2H6 containing 100 ppm H2S. This would pave the way of zeolite membranes to H-2 separation in practical applications.

Efficient recovery of CO and H-2 from offgas streams is environmentally and economically meaningful from the view point of the wide use of syngas ( CO/H-2) in the chemical industry. This work reports selective and simultaneous separation of CO and H-2 from N-2 using protic chlorocuprate ionic liquids (PCILs)-based membranes. The chemical structures of the prepared PCILs were characterized using FTIR, NMR and ESI-MS, and the thermal stability, melting points, viscosity and density of PCILs were determined. The morphology and elemental distribution of PCIL- based membranes were characterized by SEM and EDS. Facilitated transport of CO is observed in these membranes, and the CO permeability is up to 178.3 barrers (0.1 bar, 40 C-o) in [TEAH][CuCl2], with a CO/N-2 selectivity of 26.2. H-2 permeability and H-2/ N-2 selectivity are also found to reach 198.2 barrers (0.5 bar, 40 C-o) and 29.1, respectively. The permeability of CO and the selectivity of CO/N-2 can be further optimized to 405.9 barrers and 69.9 by altering the Cu(I) content, respectively. In addition, the selectivity of CO/H-2 can be tuned drastically via varying the Cu(I) content (from 0.77 to 12.0) and the operating temperature (from 2.14 to 0.42), which may be applied to the composition adjustment of syngas. In a word, this work offers a new strategy for designing IL-based membranes that used for CO and H-2 capture. (c) 2022 Elsevier Ltd. All rights reserved.

Membrane gas separation is deemed as the most energy-efficient approach to extract the rare He from natural gas. However, the techno-economic feasibility was far from the practical application because of the poor separation performance illustrated by Robeson's upper bound. Herein we reported a high-performance polymeric membrane for He extraction from natural gas. Besides the bulky Cardo segments, the pristine polymeric backbone was featured with reactive ortho-hydroxyl groups, which were thermally rearranged to benzoxazole rings benefitting micropore formation. The polymer was well dissolved in NMP then facilely coated on alpha-Al2O3 support for further thermal rearrangement. The thin and selective membrane showed He permeance of 40 GPU and He/ CH4 mixture selectivity of 74 surpassing the benchmark membranes for helium extraction. Mitigation of physical aging was demonstrated by the long-term (> 1000 h) separation in He/N2 and He/CH4 binary mixtures. The excellent He separation performance and anti-aging property endowed the membrane appealing to practical He extraction from natural gas.

Deep eutectic solvents (DESs) are environmentally friendly solvents with excellent affinity to acidic gases and have broad application prospect in the field of SO2 capture. In this work, four inexpensive DESs comprising of tetraethylammonium chloride (TEACl) and azoles (imidazole, pyrazole and tetrazole) were designed and pre -pared for highly efficient and reversible absorption of SO2. Physical properties and chemical structures of the prepared DESs were characterized. High SO2 capacity ranging from 0.756 to 1.251 g/g (3.610-7.231 mol/mol) were obtained at 20 ? and 1.0 bar. Surprisingly, owing to the accompanying phase transition, available SO2 capacity of TEACl-Im (1:3) reaches 0.438 g/g (2.532 mol/mol) at 2000 ppm and 20 ?, which is the highest value reported so far. The absorption mechanism and phase transition were further investigated using FTIR, NMR and XRD, revealing the generation and precipitation of SO2-imdazole adduct. In addition, no significant drop in SO2 absorption capacity was observed after five successive absorption-desorption cycles. Overall, TEACl-Im (1:3) exhibits good absorption performance especially for low-concentration SO2, providing potential alternatives for flue gas desulfurization.

The researches on capture of SO2 from flue gas using deep eutectic solvents (DESs) are rapidly emerging due to their unique natures, such as high efficiency and simple synthesis. However, to the best of our knowledge, DESs have not been applied to membrane separation of SO2 yet. Herein, we firstly reported novel natural deep eutectic solvent (NDES)-based gels consisting of betaine/glycerol DES (1:2) and 12-hydroxystearic acid (HSA) for selective membrane separation of SO2. Characterization of the prepared gels involving chemical structures, thermal stability and sol-gel transition temperatures were conducted. The corresponding gel membranes were facbricated and their morphology and pressure resisitance were characterized. Gas permeation test shows that the permeability of SO2 reaches 1809 barrers (0.025 bar, 40 degrees C) in DES + HSA 4% gel, with SO2/N2 and SO2/CO2 selectivities of 624 and 67.8, respectively. FTIR and NMR spectroscopy were used for characterize the facilitated transport of SO2, and the multisite-interaction mechanism was proposed. Surprisingly, the SO2 permeability is found to be significantly enhanced to 15,200 barrers without compromise on selectivity under humidified condition. Moreover, the effects of HSA content, SO2 partial pressure and temperature on separation performance were also investigated. Overall, this work offers an illustration of SO2 separation using DES-based gels, offering an alternative strategy for designing novel DES-based membrane materials for flue gas desulfuration.

Capture and storage of the long-lived 85 Kr is an efficient approach to mitigate the emission of volatile radionuclides from the spent nuclear fuel reprocessing facilities. However, it is challenging to separate krypton (Kr) from xenon (Xe) because of the chemical inertness and similar physical properties. Herein we prepared high-silica CHA zeolite membranes with ultra-high selectivity and irradiation stability for Kr/Xe separation. The suitable aperture size and rigid framework endures the membrane a strong size-exclusion effect. The ultrahigh selectivity of 51–152 together with the Kr permeance of 0.7–1.3×10 −8  mol m −2  s −1  Pa −1 of high-silica CHA zeolite membranes far surpass the state-of-the-art polymeric membranes. The membrane is among the most stable polycrystalline membranes for separation of humid Kr/Xe mixtures. Together with the excellent irradiation stability, high-silica CHA zeolite membranes pave the way to separate radioactive Kr from Xe for a notable reduction of the volatile nuclear waste storage volume.

A wood ear-derived carbon catalyst with Co components can be an efficient oxygen reduction catalyst for various fuel cells.