The coexistence of oxyanion-type and cationic heavy metals in complex aqueous systems poses a significant challenge for adsorption-based remediation. Herein, mesoporous silica-supported manganese-lanthanum mixed oxides (MnxLa1-x@MCM-41) were synthesized via an oxidation-coprecipitation strategy. The mesoporous silica framework effectively confined amorphous Mn/La oxides, suppressing oxide aggregation and manganese leaching. The as-prepared MnxLa1-x@MCM-41 materials exhibited efficient removal of heavy metals, with maximum adsorption capacities of 57.3 mg g-1 for As(V), 141.6 mg g-1 for Cd(II), and 333.0 mg g-1 for Pb(II). By adjusting the Mn/La molar ratio, the adsorption behavior toward different metal species could be systematically regulated, with La-enriched compositions favoring As(V) uptake and Mn-rich materials exhibiting enhanced affinity toward Cd(II) and Pb(II). High removal efficiencies for all three heavy metals were maintained under multicomponent coexisting conditions. The composition-dependent adsorption behavior reflects a functional differentiation of Mn-and La-associated surface sites, enabling the simultaneous immobilization of oxyanion and cationic contaminants. Overall, this work demonstrates that integrating mesoporous confinement with compositional regulation provides an effective strategy for constructing stable and multifunctional adsorbents for multicomponent heavy-metal remediation.

Developing efficient, earth-abundant photocatalytic systems for CO2 reduction is crucial for sustainable carbon utilization. Metal–organic framework (MOF) photocatalysts that integrate light harvesting and catalysis units without the need for extra photosensitizers or co-catalysts are highly attractive, yet constructing such all-in-one systems with non-noble-metal light absorbers remains a formidable challenge. Herein, we report the rational design and synthesis of the structurally well-defined Cu(I)-based rare-earth MOFs. Spectroscopic and electrochemical characterizations confirm their strong visible-light absorption and optimized energy levels for CO2 photoreduction. Remarkably, without requiring any external photosensitizers or co-catalysts, this Cu(I)-MOFs drive the selective reduction of CO2 to formate (HCOO−) with exceptional production rates of 642 μmol g−1 h−1, and an exclusive selectivity of 100%. This superior performance not only significantly outperforms previously reported amino- and porphyrin-based MOFs, but also rivals noble-metal-complex-based MOF systems. By demonstrating that an earth-abundant Cu(I) center can act as a highly efficient intrinsic photosensitizer, this work provides an innovative, additive-free strategy for developing cost-effective and high-performance photocatalysts.

One-step purification of ethylene is an important research topic in the petrochemical field, as it directly influences the energy consumption and economic efficiency of olefin production processes. In recent years, multicomponent metalorganic frameworks (MOFs), owing to their structural tunability and functional diversity, have demonstrated significant potential in C-2 hydrocarbon gas separation and purification of products from methanol-to-olefins (MTO) processes. To address the limitations of conventional single-metal-center MOFs, which often suffer from structural simplicity and restricted functionality, this work proposes a controllable construction strategy for multicomponent MOFs based on the assembly of metalligand units. Specifically, 2,2 '-biquinoline-4,4 '-dicarboxylic acid (H(2)BQDC) was employed as the organic ligand and coordinated with CuBr via an in situ reaction to form the metal-ligand unit Cu(BQDC)2. Subsequently, solvothermal reactions with ZrOCl2, Fe3O(OAc)6(H2O)(3), and Bi(NO3)3 center dot 9H2O successfully yielded three structurally well-defined multicomponent MOF materials: Zr-Cu-BQDC, Quat-Fe-Cu-BQDC, and Quat-Bi-Cu-BQDC. Comprehensive structural characterization and gas adsorption measurements reveal that the introduction of different metal centers leads to significant variations in pore size, coordination environment, and surface chemical properties, which in turn result in distinct adsorption and separation behaviors. Among them, Zr-Cu-BQDC and Quat-Fe-Cu-BQDC exhibit preferential adsorption toward C(2)H(2 )and C2H6, enabling one-step separation of high-purity C2H4 from ternary C2H2/C2H6/C2H4 mixtures. In contrast, Quat-Bi-Cu-BQDC shows stronger affinity for C3H6 and demonstrates effective separation performance for C3H6/C2H4 mixtures typically found in MTO products. The feasibility of achieving efficient one-step ethylene purification under ambient conditions was validated through single-component gas adsorption measurements, ideal adsorbed solution theory (IAST) predictions, and dynamic breakthrough experiments. This work not only develops an efficient synthesis strategy for multicomponent MOFs based on metal-ligand units and enriches the preparation pathways of multicomponent MOFs, but also provides new insights and theoreti cal guidance for the rational design of olefin separation materials tailored for practical industrial applications, highlighting both significant academic value and promising industrial potential.

Ethylene is a pivotal feedstock for the chemical industry. Obtaining polymer-grade ethylene in a single step from either binary ethane/ethylene or ternary acetylene/ethane/ethylene mixtures via porous adsorbents is highly energy-efficient yet remains a formidable challenge. Face-transitive topologies, a particular class of nets in reticular chemistry, possess only one window type and thus hold exceptional promise for discriminating between closely related C2 hydrocarbons. Guided by the nia-d topology, we synthesized two isoreticular, trinuclear-manganese-cluster-based, ternary metal-organic frameworks (MOFs), namely nia-d-TZB and nia-d-FTZB, under solvothermal conditions using MnCl2, the tritopic linker 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT), and the heterofunctional linear linkers 4-(1H-tetrazol-5-yl)benzoic acid (H2TZB) or 2-fluoro-4-(1H-tetrazol-5-yl)benzoic acid (H2FTZB). Although the resultant trigonal-bipyramidal cages remain dimensionally invariant, the introduction of fluorine in the latter linker subtly reduces the size of the antiprismatic cages and the sole triangular window in nia-d-FTZB. Single-component adsorption isotherms reveal that nia-d-TZB preferentially adsorbs ethane, whereas nia-d-FTZB preferentially adsorbs both acetylene and ethane. Consequently, nia-d-TZB enables one-step purification of ethylene from an ethane/ethylene mixture, while nia-d-FTZB achieves simultaneous removal of acetylene and ethane from an acetylene/ethane/ethylene ternary stream, again delivering polymer-grade ethylene in a single pass. These findings are corroborated by ideal adsorbed solution theory (IAST), breakthrough experiments with both binary and ternary gas mixtures, and detailed theoretical simulations. This study furnishes compelling evidence for the rational design of face-transitive MOFs to tackle complex gas-separation tasks.

The pursuit of advanced adsorbents with exceptional gas adsorption and separation capability represents a highly promising yet challenging research frontier. Several quinary multicomponent metal‐organic frameworks (MOFs) have been documented in the literature, however, the construction of quinary MOFs through the synergistic integration of two distinct organic ligands and three different metal clusters remains scarce. Herein, solvothermal reaction of Zn(OAc) 2 ·2H 2 O with adenine and 1,2,4‐benzenetricarboxylic anhydride afforded a novel MOF of Quin‐Zn‐Ad‐BTC. SCXRD reveals that Quin‐Zn‐Ad‐BTC incorporates three distinct zinc‐based structural units of a mononuclear [ZnN 2 (O 2 C─) 2 ], a dinuclear [Zn 2 (Ad) 3 (O 2 C─) 2 ], and a hexanuclear [Zn 6 N 3 ( μ ‐H 2 O) 3 (Ad) 3 (O 2 C─) 6 ], respectively. These units assemble into a novel quinary MOF structure, distinguished as the unusual material constructed from dual ligands and triple clusters. It features three interconnected cage‐like cavities replete with uncoordinated carboxylate oxygen atoms and Watson─Crick sites. Gas adsorption investigations indicate that Quin‐Zn‐Ad‐BTC demonstrates notable selectivity toward acetylene, ethane, and propylene adsorption, enabling the single‐step ethylene purification from trinary C 2 mixtures and binary MTO products. Computational simulations reveal that preferential adsorptions are facilitated by different supramolecular interaction strengths. Given its cost‐effective and readily accessible synthesis precursors, along with excellent thermal and chemical stability, Quin‐Zn‐Ad‐BTC holds great promise for advanced gas adsorption and separation applications.

Developing compact and structurally simple sensors for reliable and rapid monitoring of nitrogen dioxide (NO 2 ) remains a challenge. In this study, we synthesized a novel β ‐ketoenamine‐linked 4 + 3 covalent organic framework (COF) membrane with unique topology structure using tetrakis(4‐aminophenyl)ethene (ETTA) and 1,3,5‐triformylphloroglucinol (TP) as monomers through liquid‐liquid interfacial polymerization. The sensitive NO 2 response of the ETTA‐TP COF membrane enables the creation of the first and high‐performance NO 2 film‐based fluorescent sensor, achieving fastest response/recovery time (1.5 s/2.0 s) and a high selectivity (over 16 potential interferents). This sensor realizes a low detection limit of 0.1 ppm and a broad detection range from 0.1 to 50 ppm, while maintaining stable performance over 5000 continuous tests. Furthermore, it demonstrates on‐site, real‐time monitoring of NO 2 emissions from automotive exhaust and waste incineration. The sensing mechanism studies reveal that the carbonyl groups of β ‐ketoenamine structure can bind NO 2 via electrostatic interactions and undergoes an energy‐level‐matching photoinduced electron transfer process under photoexcitation. The responses of other carbonyl‐containing fluorescent molecules and COF materials to NO 2 corroborate the generality of this mechanism. This study offers valuable insights into the development of oxidizing gas sensors characterized by fast response time, high sensitivity, and robust in situ online monitoring capabilities.

Design and synthesis of a single metal-organic framework (MOF) that simultaneously achieves high gravimetric and volumetric working capacities for methane storage are crucial for advancing the use of natural gas as a vehicular fuel. However, this presents a significant challenge due to the inherent trade-off effect between the gravimetric and volumetric methane adsorption capacities of a single porous material. Herein, we initially synthesized a novel pyridine-carboxylic acid ligand and combined it with a trimeric iron cluster along with a series of dicarboxylic acid ligands of varying lengths or functionalities. Employing a dual-solvent system and dual-modulator solvothermal principles, we successfully constructed a 9-c ternary MOF platform. X-ray diffraction analysis reveals that the structures all feature an ncb-type topological network with a cage-channel biporous hierarchy. Through a multistep solvent exchange followed by supercritical carbon dioxide drying method, we successfully activated this series of materials, achieving substantial porosity, with pore volumes exceeding 1.90 cm3 g-1, gravimetric surface areas surpassing 4800 m2 g-1, and volumetric surface areas greater than 1600 m2 cm-3. High-pressure methane adsorption tests at 80 bar demonstrated that the series of materials exhibited a high total gravimetric and volumetric methane adsorption capacity. Notably, when the testing temperature was lowered to 273 K, these materials showed significant increases in total gravimetric and volumetric methane adsorption. Particularly, the Fe-ncb-TPDC-II constructed using the longest dicarboxylate linker achieved gravimetric and volumetric methane storage working capacities of 0.533 g g-1 and 232 cm3 (STP) cm-3, respectively, performing exceptionally well compared to reported porous materials under similar conditions.

The development of crystalline porous materials with efficient gas separation and storage capabilities is crucial for reducing energy consumption and achieving carbon neutrality, yet it remains a formidable challenge. Leveraging the advantages of cage-like structures in gas separation and storage, and based on our previous research progress in rare-earth organic frameworks, two isostructural rare-earth MOF materials were synthesized, i.e., fcu-BPyDC-Yb and fcu-BPyDC-Y, respectively. Using rare-earth ions as the metal source and a dicarboxylate ligand of 2,2'-bipyridine as the connector, both materials were successfully fabricated via solvothermal synthesis. Their structures were characterized by means of single-crystal X-ray diffraction, and their performances were evaluated through nitrogen and light hydrocarbon sorption isotherms, MTO product mixed gas breakthrough experiments, and theoretical model calculations, as well as high-pressure methane storage measurements. These results indicate that fcu-BPyDC-Y, due to its slightly larger pore sizes (9.2 vs. 8.2 Å; 16.2 vs. 15.1 Å), higher surface area (2501 vs. 2114 m2 g-1), and pore volume (0.96 vs. 0.80 cm3 g-1) compared to fcu-BPyDC-Yb, demonstrates superior propylene adsorption capacity (209.5 cm3 g-1), C3H6/C2H4 selectivity (9.1), and moderate propylene adsorption enthalpy (32.48 kJ mol-1), along with relatively high volumetric methane storage working capacity (178 cm3 (STP) cm-3).

Design and synthesis of multinary metal-organic frameworks (MOFs) are of paramount importance but challenging. Nevertheless, pore space partitioning has provided a valuable avenue to isolate ternary MOFs bearing advanced gas storage and separation properties. Herein, a rare (3,3,8)-c Fe-BQDC-BTC-TPBTC MOF was constructed by means of solvothermal reaction between iron ions, a zigzag dicarboxylate H(2)BQDC ligand and another two C-3-symmetry TPBTC and H3BTC linkers. In contrast to the frequently observed single hexagonal channel type, the acs net within Fe-BQDC-BTC-TPBTC possesses two types of hexagonal channels. One of them is capable of fitting two differently sized C-3-symmetry ligands, engendering an unusual quaternary MOF with a new partially partitioned acs 2/3-plus net eventually. Fe-BQDC-BTC-TPBTC demonstrates a complex bimodal porous system concomitant with a potential separation property toward the MTO product of ethylene and propene mixtures as verified by single gas adsorption and transient column breakthrough experiments, respectively.

In this study, we developed a reliable and atomic efficient nongaseous carbonylation protocol to synthesize flavones under mild reaction conditions. By using a controlled CO release system with Fe(CO)5 and piperazine, we adjusted the tandem reaction kinetics of the palladium-catalyzed carbonylative Sonogashira coupling and subsequent endo-cyclization. This precise control allowed for synthesis of 30 flavones with good to excellent yields via the three-component condensation of 2-iodophenols, terminal alkynes, and Fe(CO)5. The mechanism investigation under operando condition unveiled a unique homogeneous CO transfer dominated the carbonylative annulation reactions.

Achieving a balance between high selectivity and uptake is a formidable challenge for the purification of acetylene from mixtures with carbon dioxide, particularly when seeking to maximize both C2H2 adsorption capacity and C2H2/CO2 separation selectivity in crystalline porous materials. In this study, leveraging the principles of reticular chemistry, we selected two tetracarboxylate-based linkers and combined them with Cu2+ ions to synthesize two isoreticular dicopper paddle-wheel-based metal-organic frameworks (MOFs): Cu-TPTC (terphenyl-3,3',5,5'-tetracarboxylic acid, H4TPTC) and Cu-ABTC (3,3,5,5-azobenzenetetracarboxylic acid, H4ABTC). The structural and sorption analyses revealed that Cu-ABTC, despite having slightly smaller pores due to the strategic replacement of a phenyl ring with an azo group between two tetratopic ligands, maintains high porosity compared to Cu-TPTC. Furthermore, Cu-ABTC outperforms Cu-TPTC in terms of C2H2 adsorption capacity (196 cm3 g-1 at 298 K and 1 bar) and C2H2/CO2 separation selectivity (16.5~5.6). These findings were corroborated by dynamic breakthrough experiments and computational modeling. This research highlights the potential of the isoreticular contraction strategy in enhancing MOFs for sophisticated gas adsorption and separation processes.

The use of porous solid adsorbents is an effective and excellent approach for the separation and purification of methanol-to-olefins product and methane (CH4). In this particular study, a series of adenine (AD)-based biological metal–organic frameworks (Bio-MOFs) {Their general formula is Cu 2 (AD) 2 (X) 2 [X = formic acid, acetic acid (AA), and propionic acid]} were proposed, which exhibited remarkable efficiency in the purification of CH4 and the separation of C3H6 from methanol-to-olefins product, ultimately yielding purified C2H4. The experimental findings demonstrate that different terminal ligands induce alterations in the pore microenvironment, consequently leading to variations in adsorption capacities and stability. Specifically, Cu-AD-AA exhibits the highest adsorption capacity and selectivity among the three MOFs, as confirmed by static adsorption isotherm testing and theoretical evaluation using ideal adsorbed solution theory (IAST) simulation. At 298 K and 1 bar, Cu-AD-AA exhibits 786 and 10.9 selectivity for C3H8/CH4 and C3H6/C2H4, respectively, surpassing the majority of MOFs materials. Furthermore, breakthrough experiments conducted in ambient conditions reveal that Cu-AD-AA possesses commendable separation capabilities, enabling one-step purification of C2H4 at varying proportions (C2H4/C3H6 = 50:50, 50:20, and 90:10), along with satisfactory recycling performance. Importantly, the synthesis of Cu-AD-AA utilizes simple and easily obtainable raw materials, thereby offering advantages such as cost-effectiveness, low toxicity, and facile synthesis that enhance its potential for industrial applications.

The reticular chemistry of rod MOFs has attracted increasing attention from structures to applications. Herein, a series of MOF materials along with unique 3-way rod secondary building units were thoroughly prepared according to our previous work (3W-ROD-2-OH, 3W-ROD-2-F, 3W-ROD-2-CH3). Thanks to their unique structural features, 3W-ROD-2-X exhibited relatively high adsorption capacities for C3H8 (8.53 similar to 8.74 mmol/g), C2H6 (3.40 similar to 3.69 mmol/g), and CO2 (1.94 similar to 2.15 mmol/g), over CH4 (0.42 similar to 0.45 mmol/g) at 298 K and 1 bar. The adsorption selectivities of C3H8/CH4, C2H6/CH4, and CO2/CH4 were calculated by IAST. The selectivities were 53.7 similar to 70.9 (C3H8/CH4 = 15:85), 8.9 similar to 11 (C2H6/CH4 = 15:85) and 5.3 similar to 7.0 (CO2/CH4 = 15:85), respectively. Meanwhile, dynamic breakthrough experiments proved that 3W-ROD-2-CH3 showed separation property toward C3H8/CH4, C2H6/CH4, and CO2/CH4. The results indicate that the materials have the potential for natural gas upgrading.

The use of gaseous CO in Pd-catalyzed carbonylative quinolone synthesis presents challenges related to safety and precise pressure control. In response, a streamlined non-gaseous synthesis of 4-quinolone compounds has been developed. This study introduces a tunable CO-releasing system utilizing Fe(CO)5 activated by a dual-base system of piperazine and triethylamine. This alternative liquid CO resource facilitates the palladium-catalyzed carbonylative C-C coupling and subsequent intramolecular cyclization. By tuning the tandem kinetics of carbonylation and cyclization, this non-gaseous method achieves the successful synthesis of 22 distinct 4-quinolones with excellent yields. This is achieved through the three-component condensation of sub-stoichiometric amounts of Fe(CO)5 with 2-iodoaniline and terminal alkynes. Operando mechanistic studies have revealed a novel CO transfer mechanism that facilitates homogeneous carbonylative cyclization, distinguishing this method from traditional techniques. In addition to addressing safety concerns, this approach also provides precise control over selectivity, with significant implications for pharmaceutical research and the efficient synthesis of pharmaceutical and bioactive compounds.

Angular ligands are a class of important linkers to design and construct new metal-organic frameworks (MOFs). Herein, solvothermal reaction of 4,4 '-(4H-1,2,4-triazole-3,5-diyl)dibenzoic acid (TZDB), a triazole-inserted dicarboxylate, acetate, and Cu(NO3)(2)3H(2)O afforded a copper(II)-organic framework of Cu-TZDB. Structural analysis shows that Cu-TZDB displays an unusual (4,6)-c topological network concomitant with the generation of metalloligand [Cu(TZDB)(H2O)(2)] in situ. Due to its bi-channel cavities replete with triazolate, coordinated water and methyl groups, Cu-TZDB exhibits CO2 selective adsorption over N-2 and CH4, which was not only predicted by ideal adsorption solution theory (IAST), but also verified by dynamic column breakthrough tests.

Hydrogen with small molecule size under high pressure can permeate most materials, being a challenge for rubber sealing materials used in hydrogen storage. The volume expansion of rubber materials due to high-pressure hydrogen is an important indicator of their degradation and failure. Here, both microscopic calculations and experimental investigations of the nitrile rubber were conducted to evaluate the relation between the structure features and the expansion performance. Three factors, the acrylonitrile amount, the chain length, and the crosslinking degree, were considered to impact on the expansion of the nitrile rubber. Current study indicates that the increasing of acrylonitrile amount can result in the reduction of the volume expansion, owing to the preferential interactions between hydrogen and the butadiene group of nitrile rubber. Both of the chain length and the crosslinking degree are positively proportional to the chain elongation and then the volume of the nitrile rubber. Especially, the amount of acrylonitrile was found to be a key factor for evaluating the expansion of nitrile rubber under high-pressure hydrogen. This study performs microscopic calculations and macroscopic experiments to investigate the expansion of nitrile rubber, which is expected to be used in designing the sealing rubber material for high-pressure hydrogen storage applications.Highlights Acrylonitrile determines the expansion performance of NBR within high-pressure hydrogen. Short chain and low crosslinking density suppressed the expansion of NBR. Evaluating the expansion of nitrile rubber exposed to high-pressure hydrogen. Volume expansion of nitrile rubber in high-pressure hydrogen gas atmospheres. image

The efficient single-step purification of ethylene from ternary C-2 mixtures containing ethane and acetylene is challenging and demanding. Herein, we introduce a novel cerium-based metal-organic framework (MOF) of Ce-NTB-rtk synthesized via a ligand-conformer strategy. The Ce-NTB-rtk features a rare tetranuclear cerium cluster and 2D kgd layers pillared by a 3D rtl framework concomitant with an extraordinary (3,3,12)-c network. The compound encompasses microporous cavities replete with a nonpolar microenvironment. Gas sorption and breakthrough experiments demonstrate its superior affinity for C2H6 and C2H2 over C2H4, enabling effective single-step ethylene purification. Computational simulations reveal that preferential adsorptions are facilitated by different interaction strengths of C-HO hydrogen bonds. The performance of Ce-NTB-rtk in separation selectivity and regeneration capacity makes it a promising candidate for sustainable and cost-effective ethylene purification, showcasing the potential of MOFs in advanced gas separation applications.

With the development of crystalline porous materials toward methane storage, the stability issue of metal-organic framework (MOF) materials has caused great concern despite high working capacity. Considering the high stability of zirconium-based MOFs and effective functions of amide groups toward gas adsorption, herein, a series of UiO-66 type of Zr-MOFs, namely, Zr-fcu-H/F/CH3/OH, were successfully designed and synthesized by virtue of amide-functionalized dicarboxylate ligands bearing distinct side groups (i.e., -H, -F, -CH3, and -OH) and ZrCl4 in the presence of trifluoroacetic acid as the modulator. Single-crystal X-ray diffraction and topology analyses reveal that these compounds are archetypal fcu MOFs encompassing octahedral and tetrahedral cages, respectively. The N-2 sorption isotherms and acid-base stability tests demonstrate that the materials possess not only relatively high surface areas, pore volumes, and appropriate pore sizes but also great hydrolytic stabilities ranging pH = 3-11. Furthermore, the volumetric methane storage working capacities of Zr-fcu-H, Zr-fcu-F, Zr-fcu-CH3, and Zr-fcu-OH at 298/273 K and 80 bar are 187/217, 175/193, 167/187, and 154/171 cm(3) (STP) cm(-3), respectively, which indicate that the zirconium-based crystalline porous materials are capable of storing relatively high amounts of methane.

An amide-containing adenine-mediated rod metal-organic framework was solvothermally constructed by means of mixed-linker approach, which exhibits both C2H2 and C2H6 selective adsorption, resulting in one-step ethylene purification from a ternary mixture of C2H2/C2H4/C2H6 as proved by not only IAST prediction, but also column breakthrough experiments.Image 1

A series of rare-earth pillar-layered MOFs based onkgdsupermolecular building layers have been successfully isolated for the first time, with ethane-selective properties benefiting ethylene purification in a one-step process.