The preparation of porous carbon with excellent CH4/N2 adsorption and separation performance using low-rank coal as a carbon source is of great economic and environmental significance for achieving efficient methane recovery from low-concentration coalbed methane and high-value utilization of low-rank coals. However, the presence of a large amount of volatile matter in low-rank coal leads to increased KOH consumption and an uneven pore size distribution, which is detrimental to the selective adsorption separation of CH4/N2. In this work, pyrolytic pretreatment and KOH activation were combined to afford a low-rank coal based porous carbon. Compared to traditional preparation method for coal-based porous carbon, the method significantly reduced the used amount of KOH, where the alkali-to-coal mass ratio was only 1:1. Furthermore, CH4 adsorption capacity increased from 26.6 cm3/g to 37.3 cm3/g, and CH4/N2 selectivity raised from 4.8 to 5.7 at ambient temperature and pressure by pyrolytic pretreatment. Breakthrough experiments and pressure swing adsorption simulations indicated that the material has excellent CH4/N2 adsorption separation potential.

Magnesium hydride (MgH2) is regarded as an ideal material for solid-state hydrogen storage due to its high hydrogen storage capacity and safety. However, its high desorption temperature (>300 degrees C) and sluggish kinetics limit practical applications. In this study, a core-shell structured Fe3O4@NiO composite catalyst was prepared via a two-step solvothermal method and doped into MgH2 to enhance its hydrogen absorption/desorption performance. The results demonstrate that MgH2 doped with 7.5 wt% Fe3O4@NiO exhibits a reduced onset desorption temperature of 209 degrees C, which is 115 degrees C lower than that of pure MgH2. Additionally, it can release 6.19 wt% hydrogen within 5 min at 325 degrees C. The desorption activation energy decreases from 133.69 kJ/mol to 92.03 kJ/mol, indicating significant kinetic improvement. Moreover, the composite retains 98.21% of its hydrogen storage capacity after 70 absorption/desorption cycles at 300 degrees C, demonstrating excellent cyclic stability. XRD, XPS, and TEM characterizations reveal that NiO in situ forms Mg2Ni/Mg2NiH4, creating a "hydrogen pump" channel, while Fe3O4-derived Fe provides catalytic active sites. Their synergistic effect promotes hydrogen atom diffusion and Mg-H bond cleavage, thereby enhancing overall hydrogen storage performance. This study offers a novel strategy for constructing efficient and stable MgH2-based hydrogen storage systems.

Immobilizing cation-type organic molecules at the cathode represents a transformative strategy for enhancing the electrocatalytic CO2 reduction reaction (CO2RR) in acidic or pure water. However, the investigation of anion-type organic molecules is missing, and the roles of cations and anions are not well understood, especially in the membrane electrode assembly (MEA) configuration. Employing an ionic-confinement strategy mediated by a solid-state electrolyte, we systematically investigate the influence of cation- and anion-type organic molecules on CO2RR. Our findings show that cations in both cation- and anion-type molecules play a crucial role in inhibiting the hydrogen evolution reaction and promoting CO2RR in MEA. Utilizing an anion-type organic molecule, we achieved exceptional CO Faradaic efficiencies of 98.4% in H2SO4 media (pH = 1) and 95.8% in pure water-fed MEAs on Ag. Additionally, with cation-type organic molecules, we demonstrated robust operational stability of 150 h in H2SO4 (pH = 1) electrolyte and 460 h in an ultra-low potassium concentration (2 mM) acidic electrolyte in MEA configuration. This work establishes a versatile framework for achieving high-efficiency, long-term CO2 electrolysis across diverse electrolyte environments, highlighting its potential for industrial-scale application.

The separation of ethylene (C2H4) from ethane (C2H6) is a critical yet energy-intensive process in the chemical industry, demanding energy-efficient and cost-effective solutions. Here, we report a Li+-exchanged silicoaluminophosphate RHO zeolite (Li-SAPO-RHO) with unprecedented selectivity for C2H4 over C2H6. This exceptional performance is attributed to the synergy between H+ and Li+ ions strategically positioned at the flexible eight-membered ring (8MR) gates of the zeolite. These ions effectively modulate the transport barriers for C2H4 and C2H6, significantly enhancing separation efficiency. Li-SAPO-RHO exhibits an Ideal Adsorbed Solution Theory selectivity exceeding 20,000 and enables the production of polymer-grade C2H4 (>99.9%) from refinery dry gas, with a productivity of up to 238.6 mmol/L. This performance surpasses that of all existing zeolite and metal-organic framework-based benchmark adsorbents. The H+-Li+ synergistic gating effect has been investigated using advanced characterization techniques, such as electron diffraction and neutron powder diffraction, along with ab initio molecular dynamics simulations. In addition to its exceptional selectivity and productivity, Li-SAPO-RHO offers advantages of low-cost synthesis, ultrahigh stability, and excellent cyclic performance, making it a highly promising candidate for industrial-scale light olefin separations.

Adsorptive CH4/N2 separation holds great promise, yet remains a challenging effort owing to the limited availability of effective adsorbents. In this study, a series of tetramethylammonium (TMA)-modified EMT zeolites (EMT-TMA) were developed via ion exchange for CH4/N2 adsorption separation. The suitable pore and incorporated functional groups of EMT-TMA contribute to a pronounced increase in CH4 adsorption capacity, accompanied by a significant decrease in N2 adsorption, resulting in a substantial enhancement of CH4/N2 selectivity. In particular, EMT-TMA-34% exhibits a selectivity of CH4/N2 up to 5.4 at 298 K and 100 kPa, far surpassing that of the pristine EMT (1.8). Grand canonical Monte Carlo (GCMC) calculations indicate that introducing TMA markedly increases the difference for CH4 and N2 affinity on the adsorbent. Breakthrough experiments and pressure swing adsorption (PSA) simulation further confirm its outstanding CH4/N2 separation performances. This study converts previously ineffective materials in this area into highly efficient CH4 adsorbents, with significant potential for industrial coalbed methane (CBM) upgrading.

Efficiently separating acetylene (C2H2) from ternary C2H2/C2H4/CO2 mixtures represents a vital yet challenging task in the petrochemical industry, rarely accomplished with a single material. In this study, a novel ultramicroporous metal-organic frameworks (MOFs), Zn-pyc-ted, was constructed via short ligands-pyrazolecarboxylic acid (H2PYC) and triethylenediamine (ted) with multiple alkyl groups. The synthesized 3D pillar-layered framework features slit-shaped ultramicroporous channels (5.5 & Aring;) functionalized with condensed alkyl and carboxyl oxygen sites, enabling precise localization of C2H2 adsorption sites through dual-site recognition mechanisms. Adsorption studies reveal that Zn-pyc-ted exhibits remarkable C2H2 capacity of 137.2 cm(3)/g at 1 bar and 88 cm(3)/g at 0.1 bar under ambient conditions, along with exceptional selectivity for C2H2/CO2 (11.6) and C2H2/C2H4 (3.5) in equimolar mixtures, outperforming most materials in combined capacity-selectivity balance. Dynamic breakthrough experiments confirm efficient C2H2 separation from C2H4/CO2 mixtures. For Zn-pyc-ted, a dynamic C2H2 uptake of 83 cm(3)/g and high-purity productivity (>99.7%) of 8.67 L kg(-1) were achieved in an equimolar ternary mixture (C2H2/C2H4/CO2) at 298 K with a flow rate of 2 mL min(-1). Moreover, the separation performance was consistently retained across multiple cycles and under varying humidity conditions. Theoretical calculations elucidate that synergistic multiple interactions within the ultramicroporous framework critically enhance C2H2 purification.

Molybdenum disulfide (MoS2) holds great potential for gas separation in the membrane because of high aspect ratio, but its interlayer stacking leads to tortuous transport paths and a few sites, limiting the enhancement in gas separation performance. Herein, loose-stacking porous MoS2 (D-MoS2) was synthesized by liquid phase-assisted exfoliation with H2O2, whose edge effect and in-plane defect sites were exposed to improve CO2 affinity. Then, glutathione (GSH) was grafted onto the nanosheets via a thiol-click reaction to obtain glutathione-functionalized porous MoS2 (G-MoS2). Subsequently, mixed matrix composite membranes (MMCMs) were fabricated by incorporating G-MoS2 into polyvinylamine (PVAm) utilizing modified porous polysulfone membrane as a support. Notably, as-prepared MMCMs with a CO2 permeance of 648 GPU and CO2/N2 selectivity of 83 were obtained, which were the improvement of 138% and 113% over PVAm membrane, respectively, near the 2019 Robeson upper bound. This is because G-MoS2 constructs porous lamellar network structure within the membrane, which facilitates CO2 transport. Specifically, the surface pore and interlayer of G-MoS2 nanosheets can provide nanoscale selective sieving channels for CO2 to enhance gas diffusion selectivity. Meanwhile, glutathione (GSH) with active carrier sites (amine and carboxyl groups) synergistically promotes CO2 transport through the reversible reaction, improving CO2 reactivity selectivity. Besides, MMCMs maintained a stable high performance during 360 h testing using a CO2/N2 mixture, with an average CO2 permeance of 830 GPU and a CO2/N2 selectivity of 86. This indicates that constructing porous structure and specific molecular recognition microenvironments in MMCMs can provide a promising strategy for efficient CO2 separation.

Mixed matrix membranes (MMMs) have garnered significant attention on account of outstanding gas separation and mechanical properties. However, there are still challenges to achieve ideal dispersion of fillers in polymer matrix and improve CO2 plasticization properties. In this study, SPEEK-C was prepared by in-situ generating carbon dots (CDs) during the sulfonation process of poly (ether ether ketone) (PEEK), which was blended with polyvinyl alcohol (PVA) to fabricate crosslinked mixed matrix composite membranes (MMCMs) for CO2/N2 separation, named as SPEEK-C-PVA. It showed excellent CO2 separation performance, achieving the CO2 permeance of 78 GPU with the CO2/N2 selectivity of 83.9, which exceeded those of the SPEEK-PVA by 79% and 161% respectively. In-situ doping of CDs in sulfonated poly (ether ether ketone) (SPEEK) can improve the interfacial interaction between polymer matrix and inorganic materials. Moreover, the evenly-dispersed nanospace in SPEEK-C-PVA can afford the gas transport channels, which was conductive to CO2 faster transport than N2 through the membrane. Noticeably, at a feed pressure of 13 bar, SPEEK-C-PVA displayed the CO2 permeance of 58 GPU with the CO2/N2 selectivity of 72.8, which were 1.62 and 9.33 times higher than those of pristine SPEEK membrane, respectively. This demonstrates that the organic-inorganic crosslinking networks enhance the plasticization resistance of the membrane. Besides, the long-term stability test during over 200 h showed that SPEEK-C-PVA has good operating stability.

Morphology control is a powerful approach to tailor the properties of metal-organic frameworks (MOFs) for separation, catalysis, sensing, and photonics applications. However, previous efforts have primarily focused on microporous systems with pore sizes beyond typical gas dimension thresholds (>0.5 nm); the structural integrity of ultramicroporous MOFs under morphology modulation, particularly the risk of pore destruction or blockage, and their implications for molecular sieving remain insufficiently understood. Herein, we report the morphology control of an ultramicroporous MOF, Co-gallate (3.69 Å), using different kinds of surfactants. By employing cationic (cetyltrimethylammonium bromide, CTAB), nonionic (polyvinylpyrrolidone, PVP), and anionic (sodium dodecylbenzenesulfonate, SDBS) surfactants, diverse morphologies including elongated hexagonal bipyramids, microspheres, and hexagonal nanoplates are obtained. CTAB and PVP direct crystal growth via nucleation-accumulation and template-guided assembly, respectively, but both disrupt the sieving pore channels of Co-gallate due to incomplete coordination and residual surfactant blockage. Whereas SDBS micelles serve as dynamic soft templates that guide anisotropic nanoplate formation without disrupting the intrinsic sieving channels. The prepared nanoplate maintains high C2H4/C2H6 and C3H6/C3H8 sieving separation selectivity while accelerating gas adsorption kinetics due to the high aspect ratio, providing a feasible strategy to couple morphology control with preserved ultramicroporosity.

In neutral water electrolysis, the intrinsically low OH- concentration compels the oxygen evolution reaction (OER) to proceed via an additional water dissociation step, leading to sluggish kinetics and high overpotential, which poses a challenge for efficient catalyst design. Introducing Lewis base sites on the catalyst surface can act as proton acceptors, accelerating HOH bond cleavage and thereby promoting the generation and accumulation of *OH. Herein, we incorporated the Lewis base PO43- into CoWO4 to construct a self-supporting PO43--CoWO4 electrode. The incorporated PO43- engages in electronic interactions with Co/W active sites, modulating the local electronic structure. Electrochemical tests demonstrate that PO43--CoWO4 exhibits outstanding OER performance in 1 M phosphate buffer solution (PBS), achieving an overpotential of only 330 mV at 10 mA cm-2 and stable operation over 250 h. Mechanistic studies reveal that PO43- optimizes the interfacial water on CoWO4, increases the fraction of free water, facilitates water dissociation, and enhances the surface *OH coverage. Moreover, it effectively suppresses the leaching of active Co/W species during OER, thereby improving the structural stability of the catalyst. This interfacial regulation by PO43- synergistically boosts the activity and stability of neutral OER, providing new insights for designing highly efficient neutral water electrolysis catalysts.

Achieving both high activity and stability remains a key bottleneck for Ir-based catalysts in the acidic oxygen evolution reaction (OER) for proton exchange membrane water electrolyzers (PEMWEs). Herein, we present a cobalt-doped iridium oxide catalyst coated on tungsten substrate (Co-IrOx/W) fabricated via a synergistic magnetron sputtering and unipolar pulse electrodeposition strategy. The optimized catalyst demonstrates exceptional acidic OER activity with an ultralow overpotential of 209 mV at 10 mA cm-2 in 0.5 mol L-1 H2SO4, and a Ir loading only of 0.262 mg cm-2 in PEMWEs to achieve over 1000 h of stable operation at 1 A cm-2 with a degradation rate only of 6.8 & micro;V h-1. Integrated characterization reveals enhanced catalytic capacity of Co-IrOx/W in activation energy, deprotonation, and charge transfer stemmed from Co doping induced Ir d-band upward, strengthening oxygen-intermediate adsorption and accelerates OER kinetics. Moreover, the W substrate creates a W-O-Ir interfacial coordination that dynamically suppresses over-oxidation of Ir sites via electronic redistribution, thereby enhancing the stability of iridium oxide catalyst. This work offers design insights for OER catalysts to simultaneously overcome activity-stability limitations through rational electronic-structure engineering and support interactions dual design principles, opening avenues for industrial hydrogen production. (c) 2026, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

The separation of methane (CH4) from nitrogen (N2) in low-concentration coalbed methane (CBM) is crucial for efficient energy utilization and environmental protection. However, due to the similar physicochemical properties of CH4 and N2, most adsorbents exhibit limited separation performance. Herein, we report a liganddirected pore engineering strategy to enhance CH4/N2 separation in Zn-triazolate-based pillar-layered metalorganic frameworks (MOFs). A nitro-functionalized isophthalic acid linker (ipa-NO2) was introduced into a Zn2(atz)2(ipa) framework to construct Zn2(atz)2(ipa-NO2), resulting in a transition from through-layer to interlayer channels and the incorporation of adsorption sites for CH4. Compared to the parent material, Zn2(atz)2(ipa-NO2) exhibits stronger CH4 affinity, as evidenced by a higher isosteric heat of adsorption (19.52 kJ/mol) and the density functional theory (DFT) calculations. The material demonstrates a CH4/N2 selectivity exceeding 10 at 298 K and 1 bar, outperforming most of the reported CH4/N2 separation adsorbents. Excellent dynamic separation performance under both equimolar and dilute CH4 feed gas was demonstrated by breakthrough tests. This work highlights the potential of ligand-directed pore engineering in MOFs to regulate pore environment for challenging CH4/N2 separations.

Electrocatalytic nitrogen reduction reaction (ENRR) is considered as a potential pathway for green synthesis of ammonia. However, the kinetic barriers of ENRR remain a tough challenge, which is imperative to design high effective electrocatalysts for accelerated activation of N---N. Herein, the FeS/ZnS/ZIF-8-L with rich heterogeneous interfaces was successfully fabricated by governing the ordered lasso arrangement of Fe and Zn nodes in Fe-2MIM/ZIF-8-L precursor, where Fe and Zn were separately fixed in the confined space of ZIF-8-L and Fe-2MIM. Such intertwined Fe-2MIM/ZIF-8-L structure was beneficial to control the location and concentration of FeS and ZnS after sulfidation pyrolysis. The high-efficiency FeS/ZnS/ZIF-8-L exposed more catalytic active sites and possessed optimal electronic structure resulting in the lowered energy barrier of ENRR and the enhanced adsorption and activation of N2, which confirmed by experimental and theoretical characterization results. As a result, FeS/ZnS/ZIF-8-L displayed an optimal NH3 yield rate of 89.52 mu g h-1 mg-1 and Faradaic efficiency of 16.78 %, which surpassed most reported heterostructured ENRR catalysts. Our findings shed a new insight to govern the interfaces density of heterostructured electrocatalysts by predesigning the location of two metals in precursor, which can motivate an in-depth exploration to advanced catalysts for various electrocatalytic reactions.

ABSTRACT Adsorption‐based processes offer an efficient approach for the treatment of ventilation air methane (VAM). However, existing separation mechanisms typically distinguish CH 4 and N 2 based on their insignificant differences in polarizability and size, and remain largely ineffective for VAM with extremely low CH 4 concentrations. Here, we reported a clathrate‐like methane trap featuring dense arrays of electronegative O/N atoms as in methane hydrate, which exhibited electrostatic potential and shape complementarity toward CH 4 , realizing precise CH 4 recognition. The clathrate‐like methane trap exhibited a high isosteric heat of adsorption ( Q st ) of 36.0 kJ mol −1 for CH 4 , a benchmark Q st difference between CH 4 and N 2 (19.6 kJ mol −1 ), and the highest reported equilibrium‐kinetic combined selectivity (19.0). Breakthrough experiments confirmed that this trap efficiently captured CH 4 from a CH 4 /N 2 (1/99) mixture, providing a record‐high breakthrough selectivity (3.8). Its practical potential was validated by conducting a two‐bed, six‐step, variable‐pressure swing adsorption process, and 25% purity CH 4 could be obtained from a CH 4 /N 2 (1/99) mixture. In situ infrared spectroscopy and computational modelling studies revealed that the rational arrangement of dense N/O binding sites imparted a synergy between optimal pore shape and surface electrostatic potential that boosted CH 4 affinity.

Adsorption-based separation processes are of great significance for coalbed methane purification. However, most adsorbents are hydrophilic and cannot treat moist coal-mine methane. Herein, we report a hydrophobic metal-organic framework (MOF), Co-TBSC-ATC, with dense oxygen sites, constructed by a dual-ligand strategy. At 298 K and 1 bar, it exhibits a CH4 uptake of 13.2 cm3 g-1 and an ideal adsorbed solution theory (IAST) selectivity of 9.07, outperforming most hydrophobic adsorbents. Theoretical calculations revealed that the rational distribution of oxygen sites in its methyl-abundant pore channels facilitates C-H···O interactions with CH4, realizing a synergistic effect of hydrophobic resistance combined with selective adsorption. Dynamic breakthrough experiments demonstrated stable and efficient CH4/N2 separation under both dry and humid conditions, with outstanding recyclability. This work provides a feasible design strategy for hydrophobic MOFs that may be applied in the upgrading of low-grade coalbed methane.

The synthesis of imine-linked covalent organic frameworks (COF) has traditionally relied on harsh solvothermal methods, where the use of toxic organic solvents imposes a significant environmental burden and severely impedes the scalable production of COF. Thus, developing a greener and more facile synthetic approach has emerged as a critical challenge of great significance. Herein, we report a feasible solid-state “AcOH-steam-assisted synthesis” strategy, enabling the successful preparation of three imine-linked COF (SAC-TAPB-DMTP, SAC-TAPB-SHTA, and SAC-TAPB-BTCA) with high crystallinity and BET surface areas within a significantly shortened reaction time. Through tuning the pore size of these imine-linked COF, SAC-TAPB-BTCA in particular exhibits outstanding performance for CH4 purification from ternary CH4/C2H6/C3H8 mixtures, as clearly validated by gas sorption isotherms and breakthrough experiments. Computationally simulations determine the thermodynamic binding sites for each paraffin molecule, and the corresponding host-paraffin interactions are revealed using Hirshfeld surface analysis. This study enriches the synthetic strategies for imine-linked COF, offering broader opportunities in various applications.

Stable and efficient non−precious electrocatalysts are crucial for the industrialization of anion exchange membrane water electrolysis as a green hydrogen production technology. Here, we show a synergistic dual-anion engineering combining Se doping and surface [B(OH)4]− modification to overcome the activity-stability trade-off in NiFe (oxy)hydroxide. Se-doping optimizes the O 2p band center and enhances lattice oxygen participation, while [B(OH)4]− forms an interfacial hydrogen-bond network for efficient proton transfer and intermediate stabilization. This triggers a hydrogen bond-mediated oxidation mechanism, in which accelerated OH⁻ diffusion replenishes lattice oxygen dynamically while preventing vacancy accumulation. The resulting NiFe(Se)OH-BO catalyst can achieve a 177 mV overpotential at 10 mA cm−2. When serving as the anode for anion exchange membrane water electrolysis, it operates stably for >3400 h at 1 A cm−2 (70 °C), reducing hydrogen production costs to $2.28 per kg H2—surpassing the European Commission’s 2030 target and demonstrating compelling potential for a sustainable hydrogen economy. Nonprecious catalysts are vital for green hydrogen production via anion exchange membrane electrolysis. Here, the authors report a dual-anion regulation strategy in NiFe (oxy)hydroxide that enables stable operation over 3400 hours at an industrial current density of 1 A cm-2.

Carbon molecular sieve (CMS) membranes with exceptional thermal and chemical stability have emerged as a promising separation membrane for flue gas separation and coalbed methane purification. However, the nonselective and dead-end pore in the membranes impair size-sieving capacity, which restrains the increase in gas separation performance. Herein, CMS membranes (CM-Q, CM-R and CM-P) were successfully fabricated by designing the novel polyimides, which were synthesized by the copolymerization of 3,5-diaminobenzoic acid and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride with 1,4-bis(4-aminophenoxy)benzene (TPE-Q), 1,3-bis(4aminophenoxy)benzene (TPE-R) and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) respectively. Asprepared CM-Q exhibited excellent gas separation performance, with CO2, N2 and CH4 permeabilities of 7409, 713 and 245 Barrer, and CO2/N2, CO2/CH4 and N2/CH4 selectivities of 10.4, 30.2 and 2.9, respectively, exceeding the 2019 CO2/CH4 and 2008 N2/CH4 upper bounds as well as approaching the 2008 CO2/N2 upper bound. The superior gas separation performance stemmed from the precursor with regular configuration, which contributes to relatively uniform pore size for enhancing molecular sieving effect in CMS membranes. More importantly, CM-Q stored in air, mixed gas and vacuum atmosphere demonstrated the acceptable aging resistance after 30-day aging testing.

Angstrom-level pore regulation in a triazolate-based MOF is achieved through a reorientation of triazolate rings induced by amino functionalization. The resulting pore contraction effectively suppresses CH4 diffusion while preserving CO2 transport, leading to markedly enhanced CO2/CH4 selectivity.