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Indoor air pollution is one of the major threads in developed countries, notably due to high concentrations of formaldehyde, a harmful molecule difficult to eliminate. Addressing this purification challenge while adhering to the principles of sustainable development requires the use of innovative, advanced sustainable materials. Here we show that by combining state-of-the-art spectroscopic techniques with density-functional theory molecular simulations, we have developed an advantageous mild chemisorption synergistic mechanism using porous metal (III or IV) pyrazole- di-carboxylate based metal-organic framework (MOF) to trap formaldehyde in a reversible manner, without incurring significant energy penalties for regeneration. A straightforward, environmentally friendly, and scalable synthesis protocol was established for the porous, water-stable aluminum pyrazole dicarboxylate known as Al-3.5-PDA or MOF-303, capable of functioning as a highly efficient and reusable filter. It demonstrates selectivity and high storage capacity for formaldehyde under conditions typical of severe indoor use, such as in housing or vehicle cockpits, including varying VOC mixtures and concentrations, humidity, and temperature, without any accidental release. Furthermore, we have successfully regenerated this sorbent using a simple domestic protocol, ensuring the material reusability for at least 10 cycles. Indoor air pollution from harmful and carcinogenic formaldehyde is a concern in developed countries. The authors present a sustainable solution using porous Metal-Organic Frameworks (MOFs) for efficient trapping of formaldehyde and regeneration. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are porous crystalline materials that display a wide variety of physical and chemical properties. Their single crystal structure determination is often challenging because in most cases micro- or nano-sized crystals spontaneously form upon MOF synthesis, which cannot be recrystallized. The production of larger single crystals for structure determination involves optimizing, and thus modifying, the conditions of synthesis, in which success cannot be guaranteed. Failure to produce crystals suitable for single-crystal X-ray diffraction leaves the 3D structure of the MOF compound unknown, and scientists must resort to more challenging structure solution methods based on X-ray powder or electron diffraction data. These laborious tasks can be avoided by using serial crystallography techniques which merge data collected on many micro-crystals. Here, we report the application of three synchrotron serial crystallography methods. We call these "mesh", "grid" and "mesh&collect" scans. "Still" images (no rotation) are collected in the mesh scan approach, whereas small rotational wedges are collected in the grid scan method. The third protocol, mesh&collect, combines the acquisition of still images and rotational wedges. Using these means, we determine the ab initio structure of benchmark MOFs, MIL-100(Fe) and ZIF-8, that differ largely in unit cell size. These methods are expected to be widely applicable and facilitate structure determination of many MOF microcrystalline systems. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) show captivating performances in many large‐scale applications including gas adsorption and separation, heat reallocation, water production, or remediation which can overcome important drawbacks of the conventionally used porous materials in the industry. This raises, therefore, the commercial interest in MOFs which brings the necessity to decrease the cost of their production, calling for the synthesis optimization from small‐scale to large‐scale. However, the commercial availability, yet very limited, is highly dependent on their production cost. Thus, to promote the commercial development and availability of MOFs, many steps can be taken. In this work, the state‐of‐art of the large‐scale production of MOFs can be first outlined, before discussing the criteria of greener MOF synthesis processes. Besides, a critical evaluation of the available synthesis routes for large‐scale production can be given, taking into consideration their cost, environmental impact, safety, and feasibility. Moreover, since there are strong limitations to the use in the powder form, the shaping procedures can thus be discussed briefly to outline the prospects of MOFs for different industrial applications. Finally, yet importantly, the perspective for MOFs commercialization can be highlighted with an emphasis on the necessity of techno‐economic analyses and life‐cycle assessments. [ABSTRACT FROM AUTHOR]

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Reducing carbon dioxide (CO2) emissions urgently requires the large-scale deployment of carbon-capture technologies. These technologies must separate CO2 from various sources and deliver it to different sinks1,2. The quest for optimal solutions for specific source–sink pairs is a complex, multi-objective challenge involving multiple stakeholders and depends on social, economic and regional contexts. Currently, research follows a sequential approach: chemists focus on materials design3 and engineers on optimizing processes4,5, which are then operated at a scale that impacts the economy and the environment. Assessing these impacts, such as the greenhouse gas emissions over the plant’s lifetime, is typically one of the final steps6. Here we introduce the PrISMa (Process-Informed design of tailor-made Sorbent Materials) platform, which integrates materials, process design, techno-economics and life-cycle assessment. We compare more than 60 case studies capturing CO2 from various sources in 5 global regions using different technologies. The platform simultaneously informs various stakeholders about the cost-effectiveness of technologies, process configurations and locations, reveals the molecular characteristics of the top-performing sorbents, and provides insights on environmental impacts, co-benefits and trade-offs. By uniting stakeholders at an early research stage, PrISMa accelerates carbon-capture technology development during this critical period as we aim for a net-zero world.A framework that integrates materials, process design, techno-economics and life-cycle assessment can be used to accelerate the development of carbon-capture technology as we aim for a net-zero world. [ABSTRACT FROM AUTHOR]

We present here the encapsulation of a spin crossover complex C1 [FeII(L)] (L: 4‐amino‐, 2‐(2‐pyridinylmethylene)hydrazide) inside MOF‐808(Zr), a chemically robust Metal‐Organic Framework. The compound C1⊂MOF‐808 retains its crystallinity as well as a partial porosity compared to pristine MOF and shows solvatochromism under Volatile Organic compounds (VOCs) sorption associated to a spin state change of the guest complex. More specifically, this compound shows an interesting reversible color change under formaldehyde and formic acid vapor sorption and can therefore be considered as a new kind of optical VOCs chemosensor, opening new doors for developing a broad range of VOCs optical sensors. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are considered as promising candidates for next‐generation energy storage devices for grid applications due to their high theoretical energy density. However, the inevitable shuttle effect of lithium polysulfides and/or dendrite growth of Li metal anodes hinder their commercial viability. Herein, the microporous Zr fumarate metal–organic framework (MOF)‐801(Zr) is considered to produce thin (≈15.6 μm, ≈1 mg cm2) mixed‐matrix membranes (MMM) as a novel interlayer for Li–S batteries. It is found that the MOF‐801(Zr)/C/PVDF‐HFP composite interlayer facilitates Li+ ions diffusion, and anchors polysulfides while promoting their redox conversion effectively. It is demonstrated that MOF‐801 effectively trapped polysulfides at the cathode side, and confirmed for the first time the nature of the interaction between the adsorbed polysulfides and the host framework, through a combination of solid‐state nuclear magnetic resonance and molecular dynamics simulations. The incorporation of MOF‐801(Zr)/C/PVDF‐HFP MMM interlayer results in a notable enhancement in the initial capacity of Li–S batteries up to 1110 mA h g−1. Moreover, even after 50 cycles, a specific capacity of 880 mA h g−1 is delivered. [ABSTRACT FROM AUTHOR]

The size and defects in crystalline inorganic materials are of importance in many applications, particularly catalysis, as it often results in enhanced/emerging properties. So far, applying the strategy of modulation chemistry has been unable to afford high-quality functional Metal–Organic Frameworks (MOFs) nanocrystals with minimized size while exhibiting maximized defects. We report here a general sustainable strategy for the design of highly defective and ultra-small tetravalent MOFs (Zr, Hf) crystals (ca. 35% missing linker, 4–6 nm). Advanced characterizations have been performed to shed light on the main factors governing the crystallization mechanism and to identify the nature of the defects. The ultra-small nanoMOFs showed exceptional performance in peptide hydrolysis reaction, including high reactivity, selectivity, diffusion, stability, and show emerging tailorable reactivity and selectivity towards peptide bond formation simply by changing the reaction solvent. Therefore, these highly defective ultra-small M(IV)-MOFs particles open new perspectives for the development of heterogeneous MOF catalysts with dual functions. Crystalline materials' properties are highly dependent on their size. Here authors report a general synthesis of ultrasmall (4–6 nm) and highly defective Zr/Hf-Metal Organic Frameworks nanoparticles that present enhanced peptide hydrolysis performance. [ABSTRACT FROM AUTHOR]

The improvement of the Total Isomerization Process (TIP) for the production of high‐quality gasoline with the ultimate goal of reaching a Research Octane Number (RON) higher than 92 requires the use of specific sorbents to separate pentane and hexane isomers into classes of linear, mono‐ and di‐branched isomers. Herein we report the design of a new multi‐cage microporous Fe(III)‐MOF (referred to as MIP‐214, MIP stands for materials of the Institute of Porous Materials of Paris) with a flu‐e topology, incorporating an asymmetric heterofunctional ditopic ligand, 4‐pyrazolecarboxylic acid, that exhibits an appropriate microporous structure for a thermodynamic‐controlled separation of hydrocarbon isomers. This MOF produced via a direct, scalable, and mild synthesis route was proven to encompass a unique separation of C5/C6 isomers by classes of low RON over high RON alkanes with a sorption hierarchy: (n‐hexane≫n‐pentane≈2‐methylpentane>3‐methylpentane)low RON≫(2,3‐dimethylbutane≈i‐pentane≈2,2‐dimethylbutane)high RON following the adsorption enthalpy sequence. We reveal for the first time that a single sorbent can efficiently separate such a complex mixture of high RON di‐branched hexane and mono‐branched pentane isomers from their low RON counterparts, which is a major achievement reported so far. [ABSTRACT FROM AUTHOR]

The improvement of the Total Isomerization Process (TIP) for the production of high‐quality gasoline with the ultimate goal of reaching a Research Octane Number (RON) higher than 92 requires the use of specific sorbents to separate pentane and hexane isomers into classes of linear, mono‐ and di‐branched isomers. Herein we report the design of a new multi‐cage microporous Fe(III)‐MOF (referred to as MIP‐214, MIP stands for materials of the Institute of Porous Materials of Paris) with a flu‐e topology, incorporating an asymmetric heterofunctional ditopic ligand, 4‐pyrazolecarboxylic acid, that exhibits an appropriate microporous structure for a thermodynamic‐controlled separation of hydrocarbon isomers. This MOF produced via a direct, scalable, and mild synthesis route was proven to encompass a unique separation of C5/C6 isomers by classes of low RON over high RON alkanes with a sorption hierarchy: (n‐hexane≫n‐pentane≈2‐methylpentane>3‐methylpentane)low RON≫(2,3‐dimethylbutane≈i‐pentane≈2,2‐dimethylbutane)high RON following the adsorption enthalpy sequence. We reveal for the first time that a single sorbent can efficiently separate such a complex mixture of high RON di‐branched hexane and mono‐branched pentane isomers from their low RON counterparts, which is a major achievement reported so far. [ABSTRACT FROM AUTHOR]

Owing to their high porosity and tunability, porous solids such as metal–organic frameworks (MOFs), zeolites, or activated carbons (ACs) are of great interest in the fields of air purification, gas separation, and catalysis, among others. Nonetheless, these materials are usually synthetized as powders and need to be shaped in a more practical way that does not modify their intrinsic property (i.e., porosity). Elaborating porous, freestanding and flexible sheets is a relevant shaping strategy. However, when high loadings (>70 wt.%) are achieved the mechanical properties are challenged. A new straightforward and green method involving the combination softwood bleached kraft pulp fibers (S) and nano‐fibrillated cellulose (NFC) is reported, where S provides flexibility while NFC acts as a micro‐structuring and mechanical reinforcement agent to form high loadings porous solids paper sheets (>70 wt.%). The composite has unobstructed porosity and good mechanical strength. The sheets prepared with various fillers (MOFs, ACs, and zeolites) can be rolled, handled, and adapted to different uses, such as air purification. As an example of potential application, a MOF paper composite has been considered for the capture of polar volatile organic compounds exhibiting better performance than beads and granules. [ABSTRACT FROM AUTHOR]

Al-based cationic metal-organic frameworks (MOFs) are uncommon. Here, we report a cationic Al-MOF, MIP-213(Al) ([Al18(μ2-OH)24(OH2)12(mdip)6]6Cl·6H2O) constructed from flexible tetra-carboxylate ligand (5,5'-Methylenediisophthalic acid; H4mdip). Its crystal structure was determined by the combination of three-dimensional electron diffraction (3DED) and high-resolution powder X-ray diffraction. The structure is built from infinite corner-sharing chains of AlO4(OH)2 and AlO2(OH)3(H2O) octahedra forming an 18-membered rings honeycomb lattice, similar to that of MIL-96(Al), a scarce Al-polycarboxylate defective MOF. Despite sharing these structural similarities, MIP-213(Al), unlike MIL-96(Al), lacks the isolated μ3-oxo-bridged Al-clusters. This leads to an ordered defective cationic framework whose charge is balanced by Cl- sandwiched between two Al-trimers at the corner of the honeycomb, showing strong interaction with terminal H2O coordinated to the Al-trimers. The overall structure is endowed by a narrow quasi-1D channel of dimension ~4.7 Å. The Cl- in the framework restrains the accessibility of the channels, while the MOF selectively adsorbs CO2 over N2 and possesses high hydrolytic stability. Aluminium-based cationic metal–organic frameworks remain rare, yet offer opportunities for unusual framework structures and material properties. Here, a robust ultra-microporous cationic metal–organic framework based on aluminium building units and flexible tetracarboxylic acid linkers is reported, and three-dimensional electron diffraction combined with high-resolution powder X-ray diffraction show that the material comprises an ordered defective cationic framework with narrow quasi-1D channels. [ABSTRACT FROM AUTHOR]

Recent breakthrough experiments revealed the iso-reticular Zr-MOFs, MIL-140B and MIL-140C, as promising sorbents for the separation of C6 isomers. Interestingly while the ultra-small pore MIL-140B exhibited hexane isomer sorption hierarchy according to the normal boiling point order (n-C6 > 3MP (3-methyl pentane)), an uncommon shift in the elution order was observed in the larger pore MIL-140C. It was only speculated that the flexibility of the MOFs might be the origin of this intriguing behavior. Herein, flexible force field hybrid osmotic Monte Carlo combined with molecular dynamics simulations were carried out to unravel the microscopic mechanism of the adsorption and dynamics of both C6 isomers in MIL140B and MIL140C. Thermodynamically preferred adsorption of n-C6 over 3MP was predicted for MIL-140B and to a slightly less extent for MIL-140C. Interestingly while the mobility of n-C6 was found to remain higher than that of 3MP in the whole range of loading for MIL-140B, 3MP becomes more mobile than n-C6 at saturation in MIL-140C. This suggests that this kinetics order is most probably the origin of the inversion of the elution order observed experimentally for MIL-140C. The translational and rotational dynamics of the two guests in MIL-140B and MIL-140C was further understood in-depth. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are a highly versatile class of ordered porous materials, which hold great promise for different biomedical applications, including antibacterial therapy. In light of the antibacterial effects, these nanomaterials can be attractive for several reasons. First, MOFs exhibit a high loading capacity for numerous antibacterial drugs, including antibiotics, photosensitizers, and/or photothermal molecules. The inherent micro- or meso-porosity of MOF structures enables their use as nanocarriers for simultaneous encapsulation of multiple drugs resulting in a combined therapeutic effect. In addition to being encapsulated into an MOF's pores, antibacterial agents can sometimes be directly incorporated into an MOF skeleton as organic linkers. Next, MOFs contain coordinated metal ions in their structure. Incorporation of Fe2/3+, Cu2+, Zn2+, Co2+, and Ag+ can significantly increase the innate cytotoxicity of these materials for bacteria and cause a synergistic effect. Finally, abundance of functional groups enables modifying the external surface of MOF particles with stealth coating and ligand moieties for improved drug delivery. To date, there are a number of MOF-based nanomedicines available for the treatment of bacterial infections. This review is focused on biomedical consideration of MOF nano-formulations designed for the therapy of intracellular infections such as Staphylococcus aureus, Mycobacterium tuberculosis, and Chlamydia trachomatis. Increasing knowledge about the ability of MOF nanoparticles to accumulate in a pathogen intracellular niche in the host cells provides an excellent opportunity to use MOF-based nanomedicines for the eradication of persistent infections. Here, we discuss advantages and current limitations of MOFs, their clinical significance, and their prospects for the treatment of the mentioned infections. [ABSTRACT FROM AUTHOR]

A new process, PMOFSA, is described here, that opens the way for the one-pot straightforward and versatile manufacture of polymer-MOF nanoparticles in water. It can be expected that this study will not only expand the scope of in situ preparation of polymer-MOF nano-objects but also inspire researchers in the field to prepare a new generation of polymer-MOF hybrid materials. [ABSTRACT FROM AUTHOR]

Among a plethora of drug nanocarriers, biocompatible nanoscale metal–organic frameworks (nanoMOFs) with a large surface area and an amphiphilic internal microenvironment have emerged as promising drug delivery platforms, mainly for cancer therapy. However, their application in biomedicine still suffers from shortcomings such as a limited chemical and/or colloidal stability and/or toxicity. Here, we report the design of a hierarchically porous nano-object (denoted as USPIO@MIL) combining a benchmark nanoMOF (that is, MIL-100(Fe)) and ultra-small superparamagnetic iron oxide (USPIO) nanoparticles (that is, maghemite) that is synthesized through a one-pot, cost-effective and environmentally friendly protocol. The synergistic coupling of the physico-chemical and functional properties of both nanoparticles confers to these nano-objects valuable features such as high colloidal stability, high biodegradability, low toxicity, high drug loading capacity as well as stimuli-responsive drug release and superparamagnetic properties. This bimodal MIL-100(Fe)/maghemite nanocarrier once loaded with anti-tumoral and anti-inflammatory drugs (doxorubicin and methotrexate) shows high anti-inflammatory and anti-tumoral activities. In addition, the USPIO@MIL nano-object exhibits excellent relaxometric properties and its applicability as an efficient contrast agent for magnetic resonance imaging is herein demonstrated. This highlights the high potential of the maghemite@MOF composite integrating the functions of imaging and therapy as a theranostic anti-inflammatory formulation. [ABSTRACT FROM AUTHOR]

Effective capture of polar volatile organic compounds under environmental conditions is a challenge owing to the adsorption competition between polar volatile organic compounds and water. The best adsorbents usually exhibit a compromise between a moderate affinity towards the VOC and hydrophobicity. Herein, by conducting experimental (sorption isotherms, dynamic measurements, X-ray diffraction, and solid-state NMR) and computational (Monte Carlo and density functional theory) studies, we demonstrate that introducing perfluorinated groups within the flexible microporous MOF increases hydrophobicity and its MIL-53(Al) MOF increases hydrophobilicty and leads to higher affinity to VOCs. Remarkably, MIL-53(Al)-CF3 exhibits an outstanding affinity for acetic acid even in the presence of water, while its MIL-53(Al)-2CF3 analogue, owing to steric hindrance, is not efficient. Therefore, perfluorinated flexible MIL-53(Al) with one CF3 group appears as an optimum sorbent for indoor air quality management under real working conditions, especially for high-end applications that require the removal of trace levels of VOCs under environmental conditions. [ABSTRACT FROM AUTHOR]

Countless people have been affected by the COVID‐19 pandemic on a global scale. Favipiravir, has shown potential as an effective drug for SARS‐CoV‐2, attracting scientists' attention. However, overuse of Favipiravir easily leads to serious side effects, requiring real‐time monitoring in body fluids. Given this, a new lanthanide metal‐organic framework (MOF) was prepared under solvothermal conditions from either Eu (Eu‐MOF or (1)) or Tb (Tb‐MOF or (2)) using the highly delocalized imidazoledicarboxylic acid linker H2L (H2L=5‐(4‐(imidazol‐1‐yl) phenyl) isophthalic acid) and could be successfully applied to selective optical detection of Favipiravir. In this MOF framework, the organic linker H2L provides a high excitation energy transfer efficiency that can sensitize luminescence in lanthanides. In addition, through deliberate tuning of Eu/Tb molar ratio and reaction concentration in the lanthanide framework, ratiometric recyclable luminescent EuxTb1‐x‐MOF nanoparticles with open metal sites have been constructed, which present a high detection sensitivity (Ksv=1×107 [M−1], detection limit is 4.63 nM) for Favipiravir. The detection mechanism is discussed with the help of Density Functional Theory (DFT) calculations that sheds light over the selective sensing of Favipiravir over other related COVID‐19 drug candidates. Finally, to explore the practical application of Favipiravir sensing, MOF based thin films have been used for visual detection of Favipiravir and recycled 5 times. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) attract growing interest in biomedical applications. Among thousands of MOF structures, the mesoporous iron(III) carboxylate MIL-100(Fe) (MIL stands for the Materials of Lavoisier Institute) is among the most studied MOF nanocarrier, owing to its high porosity, biodegradability, and lack of toxicity. Nanosized MIL-100(Fe) particles (nanoMOFs) readily coordinate with drugs leading to unprecedented payloads and controlled release. Here, we show how the functional groups of the challenging anticancer drug prednisolone influence their interactions with the nanoMOFs and their release in various media. Molecular modeling enabled predicting the strength of interactions between prednisolone-bearing or not phosphate or sulfate moieties (PP and PS, respectively) and the oxo-trimer of MIL-100(Fe) as well as understanding the pore filling of MIL-100(Fe). Noticeably, PP showed the strongest interactions (drug loading up to 30 wt %, encapsulation efficiency > 98%) and slowed down the nanoMOFs' degradation in simulated body fluid. This drug was shown to bind to the iron Lewis acid sites and was not displaced by other ions in the suspension media. On the contrary, PS was entrapped with lower efficiencies and was easily displaced by phosphates in the release media. Noticeably, the nanoMOFs maintained their size and faceted structures after drug loading and even after degradation in blood or serum after losing almost the totality of the constitutive trimesate ligands. Scanning electron microscopy with high annular dark field (STEM-HAADF) in conjunction with X-Ray energy-dispersive spectrometry (XEDS) was a powerful tool enabling the unraveling of the main elements to gain insights on the MOF structural evolution after drug loading and/or upon degradation. [ABSTRACT FROM AUTHOR]

Metal–Organic Frameworks (MOFs) with open metal sites (OMS) interact strongly with a range of polar gases/vapors. However, under ambient conditions, their selective adsorption is generally impaired due to a high OMS affinity to water. This led previously to the privilege selection of hydrophobic MOFs for the selective capture/detection of volatile organic compounds (VOCs). Herein, we show that this paradigm is challenged by metal(III) polycarboxylates MOFs, bearing a high concentration of OMS, as MIL‐100(Fe), enabling the selective capture of polar VOCs even in the presence of water. With experimental and computational tools, including single‐component gravimetric and dynamic mixture adsorption measurements, in situ infrared (IR) spectroscopy and Density Functional Theory calculations we reveal that this adsorption mechanism involves a direct coordination of the VOC on the OMS, associated with an interaction energy that exceeds that of water. Hence, MOFs with OMS are demonstrated to be of interest for air purification purposes. [ABSTRACT FROM AUTHOR]

Metal–Organic Frameworks (MOFs) with open metal sites (OMS) interact strongly with a range of polar gases/vapors. However, under ambient conditions, their selective adsorption is generally impaired due to a high OMS affinity to water. This led previously to the privilege selection of hydrophobic MOFs for the selective capture/detection of volatile organic compounds (VOCs). Herein, we show that this paradigm is challenged by metal(III) polycarboxylates MOFs, bearing a high concentration of OMS, as MIL‐100(Fe), enabling the selective capture of polar VOCs even in the presence of water. With experimental and computational tools, including single‐component gravimetric and dynamic mixture adsorption measurements, in situ infrared (IR) spectroscopy and Density Functional Theory calculations we reveal that this adsorption mechanism involves a direct coordination of the VOC on the OMS, associated with an interaction energy that exceeds that of water. Hence, MOFs with OMS are demonstrated to be of interest for air purification purposes. [ABSTRACT FROM AUTHOR]

Encapsulating ultrasmall Cu nanoparticles inside Zr‐MOFs to form core–shell architecture is very challenging but of interest for CO2 reduction. We report for the first time the incorporation of ultrasmall Cu NCs into a series of benchmark Zr‐MOFs, without Cu NCs aggregation, via a scalable room temperature fabrication approach. The Cu NCs@MOFs core–shell composites show much enhanced reactivity in comparison to the Cu NCs confined in the pore of MOFs, regardless of their very similar intrinsic properties at the atomic level. Moreover, introducing polar groups on the MOF structure can further improve both the catalytic reactivity and selectivity. Mechanistic investigation reveals that the CuI sites located at the interface between Cu NCs and support serve as the active sites and efficiently catalyze CO2 photoreduction. This synergetic effect may pave the way for the design of low‐cost and efficient catalysts for CO2 photoreduction into high‐value chemical feedstock. [ABSTRACT FROM AUTHOR]

Encapsulating ultrasmall Cu nanoparticles inside Zr‐MOFs to form core–shell architecture is very challenging but of interest for CO2 reduction. We report for the first time the incorporation of ultrasmall Cu NCs into a series of benchmark Zr‐MOFs, without Cu NCs aggregation, via a scalable room temperature fabrication approach. The Cu NCs@MOFs core–shell composites show much enhanced reactivity in comparison to the Cu NCs confined in the pore of MOFs, regardless of their very similar intrinsic properties at the atomic level. Moreover, introducing polar groups on the MOF structure can further improve both the catalytic reactivity and selectivity. Mechanistic investigation reveals that the CuI sites located at the interface between Cu NCs and support serve as the active sites and efficiently catalyze CO2 photoreduction. This synergetic effect may pave the way for the design of low‐cost and efficient catalysts for CO2 photoreduction into high‐value chemical feedstock. [ABSTRACT FROM AUTHOR]

Zeolites and metal‐organic frameworks (MOFs) are considered as "competitors" for new separation processes. The production of high‐quality gasoline is currently achieved through the total isomerization process that separates pentane and hexane isomers while not reaching the ultimate goal of a research octane number (RON) higher than 92. This work demonstrates how a synergistic action of the zeolite 5A and the MIL‐160(Al) MOF leads to a novel adsorptive process for octane upgrading of gasoline through an efficient separation of isomers. This innovative mixed‐bed adsorbent strategy encompasses a thermodynamically driven separation of hexane isomers according to the degree of branching by MIL‐160(Al) coupled to a steric rejection of linear isomers by the molecular sieve zeolite 5A. Their adsorptive separation ability is further evaluated under real conditions by sorption breakthrough and continuous cyclic experiments with a mixed bed of shaped adsorbents. Remarkably, at the industrially relevant temperature of 423 K, an ideal sorption hierarchy of low RON over high RON alkanes is achieved, i.e., n‐hexane ≫ n‐pentane ≫ 2‐methylpentane > 3‐methylpentane ⋙ 2,3‐dimethylbutane > isopentane ≈ 2,2‐dimethylbutane, together with a productivity of 1.14 mol dm−3 and a high RON of 92, which is a leap‐forward compared with existing processes. [ABSTRACT FROM AUTHOR]

Zeolites and metal‐organic frameworks (MOFs) are considered as "competitors" for new separation processes. The production of high‐quality gasoline is currently achieved through the total isomerization process that separates pentane and hexane isomers while not reaching the ultimate goal of a research octane number (RON) higher than 92. This work demonstrates how a synergistic action of the zeolite 5A and the MIL‐160(Al) MOF leads to a novel adsorptive process for octane upgrading of gasoline through an efficient separation of isomers. This innovative mixed‐bed adsorbent strategy encompasses a thermodynamically driven separation of hexane isomers according to the degree of branching by MIL‐160(Al) coupled to a steric rejection of linear isomers by the molecular sieve zeolite 5A. Their adsorptive separation ability is further evaluated under real conditions by sorption breakthrough and continuous cyclic experiments with a mixed bed of shaped adsorbents. Remarkably, at the industrially relevant temperature of 423 K, an ideal sorption hierarchy of low RON over high RON alkanes is achieved, i.e., n‐hexane ≫ n‐pentane ≫ 2‐methylpentane > 3‐methylpentane ⋙ 2,3‐dimethylbutane > isopentane ≈ 2,2‐dimethylbutane, together with a productivity of 1.14 mol dm−3 and a high RON of 92, which is a leap‐forward compared with existing processes. [ABSTRACT FROM AUTHOR]

Nanoparticles of metal–organic frameworks (MOF NPs) are crystalline hybrid micro- or mesoporous nanomaterials that show great promise in biomedicine due to their significant drug loading ability and controlled release. Herein, we develop porous capsules from aggregate of nanoparticles of the iron carboxylate MIL-100(Fe) through a low-temperature spray-drying route. This enables the concomitant one-pot encapsulation of high loading of an antitumor drug, methotrexate, within the pores of the MOF NPs, and the collagenase enzyme (COL), inside the inter-particular mesoporous cavities, upon the formation of the capsule, enhancing tumor treatment. This association provides better control of the release of the active moieties, MTX and collagenase, in simulated body fluid conditions in comparison with the bare MOF NPs. In addition, the loaded MIL-100 capsules present, against the A-375 cancer cell line, selective toxicity nine times higher than for the normal HaCaT cells, suggesting that MTX@COL@MIL-100 capsules may have potential application in the selective treatment of cancer cells. We highlight that an appropriate level of collagenase activity remained after encapsulation using the spray dryer equipment. Therefore, this work describes a novel application of MOF-based capsules as a dual drug delivery system for cancer treatment. [ABSTRACT FROM AUTHOR]

The realization of metal‐organic framework (MOF) layers onto solid surfaces is a prerequisite for their integration into devices. This work reports the direct growth of Fe3+/benzene di‐carboxylate MOFs onto functionalized silicon surfaces, compatible with a wide range of MOF synthesis conditions. The co‐nucleation and growth of different crystalline phases are evidenced, whose coverage depends on the surface chemistry and/or the solution composition. Three structural phases – the cubic MIL‐101(Fe), a hexagonal phase with a structure close to MOF‐235 and a MIL‐53(Fe) with a monoclinic symmetry ‐ are identified through characteristic crystal shapes and their structural parameters inferred from X‐Ray Diffraction. In addition to the oriented growth of 3D crystallites, the formation of two‐dimensional MIL‐101 nano‐crystallites or thin layers/islands exhibiting extended monocrystalline domains with (111) texture is also demonstrated through high‐resolution atomic force microscopy. Post‐synthesis treatments reveal a weak adhesion of the hexagonal phase, indicating a different surface anchoring. [ABSTRACT FROM AUTHOR]

External control over the pore size of flexible metal–organic frameworks (MOFs) has recently emerged as an intriguing concept, with possible applications to gas storage and separation. In this work we present a new pressure cell capable for the first time of monitoring through in situ X‐ray powder diffraction an adsorbent powder under combined uniaxial applied mechanical stress (up to 1 GPa) and gas pressure (up to 20 bar). The combined stress–pressure clamp (CSPC) cell was successfully exploited to follow the evolution of the CO2 breathing behaviour of the prototypical complex breathing MIL‐53(Al) system under mechanical compression obtaining structural evidence that this MOF can be maintained in its closed pore state upon compression, precluding its re‐opening at high gas pressure (>7 bar). This novel setup shows potential for the in‐operando exploration of flexible systems, in equilibrium and flow configurations. [ABSTRACT FROM AUTHOR]

External control over the pore size of flexible metal–organic frameworks (MOFs) has recently emerged as an intriguing concept, with possible applications to gas storage and separation. In this work we present a new pressure cell capable for the first time of monitoring through in situ X‐ray powder diffraction an adsorbent powder under combined uniaxial applied mechanical stress (up to 1 GPa) and gas pressure (up to 20 bar). The combined stress–pressure clamp (CSPC) cell was successfully exploited to follow the evolution of the CO2 breathing behaviour of the prototypical complex breathing MIL‐53(Al) system under mechanical compression obtaining structural evidence that this MOF can be maintained in its closed pore state upon compression, precluding its re‐opening at high gas pressure (>7 bar). This novel setup shows potential for the in‐operando exploration of flexible systems, in equilibrium and flow configurations. [ABSTRACT FROM AUTHOR]

The discovery of nanozymes for selective fragmentation of proteins would boost the emerging areas of modern proteomics, however, the development of efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. Here we report the catalytic properties of a zirconium metal-organic framework, MIP-201, in promoting peptide bond hydrolysis in a simple dipeptide, as well as in horse-heart myoglobin (Mb) protein that consists of 153 amino acids. We demonstrate that MIP-201 features excellent catalytic activity and selectivity, good tolerance toward reaction conditions covering a wide range of pH values, and importantly, exceptional recycling ability associated with easy regeneration process. Taking into account the catalytic performance of MIP-201 and its other advantages such as 6-connected Zr6 cluster active sites, the green, scalable and cost-effective synthesis, and good chemical and architectural stability, our findings suggest that MIP-201 may be a promising and practical alternative to commercially available catalysts for peptide bond hydrolysis. Developing efficient and reusable artificial catalysts for peptide bond hydrolysis is challenging. This work presents the catalytic properties of a Zr-MOF, MIP-201, which features excellent catalytic activity and selectivity, good condition tolerance, and exceptional recycling ability. [ABSTRACT FROM AUTHOR]

Metal nanoparticles encased in a MOF shell have shown remarkable properties in catalysis due to potential synergistic effects. However, capping agents, commonly used to prepare these nanoparticles, lower their reactivity once embedded into the MOF. Here we present a new route to prepare polyvinylpyrrolidone (PVP)-capped Au NPs@MOF-808 core–shell composites. Simultaneously, we show for the first time that the capping PVP can be easily removed by chemical treatment while maintaining the integrity of the MOF shell. We finally show how this leads to a significant enhancement of the reactivity of Au NPs@MOF-808 composites for selective oxidation reactions. [ABSTRACT FROM AUTHOR]

Encapsulation of active guest compounds inside metal–organic frameworks (MOFs) architectures is one of the most promising routes to reach properties beyond those of the bare MOFs and/or guest species. In contrast with the conventional host/guest composites that rely on the encapsulation of guest species into MOF cavities, core–shell composites display a better accessibility to the pores ensuring an optimal diffusion of the substrate while presenting a unique structure that prevents the aggregation and the runoff of the active guests and ensures a tight interaction between core and shell, leading to synergistic effects. Herein, the recent advances in this field are summarized. The main synthetic strategies are first discussed before highlighting a few potential applications, such as heterogeneous environmental catalysis, gas separation, and sensing, while others (bio‐applications...) are briefly mentioned. This review is concluded by a critical perspective in order to promote new generations of MOFs based composites for energy‐related applications. [ABSTRACT FROM AUTHOR]

In the last two decades, the field of metal–organic frameworks (MOFs) has exploded, and MOF nanoparticles in particular are being investigated with increasing interest for various applications, including gas storage and separation, water harvesting, catalysis, energy conversion and storage, sensing, diagnosis, therapy, and theranostics. To further pave their way into real-world applications, and to push the synthesis of MOF nanoparticles that are 'safe-and-sustainable-by-design', this tutorial review aims to shed light on the importance of a systematic toxicity assessment. After clarifying and working out the most important terms and aspects from the field of nanotoxicity, the current state-of-the-art of in vitro and in vivo toxicity studies of MOF nanoparticles is evaluated. Moreover, the key aspects affecting the toxicity of MOF nanoparticles such as their chemical composition, their physico-chemical properties, including their colloidal and chemical stability, are discussed. We highlight the need of more targeted synthesis of MOF nanoparticles that are 'safe-and-sustainable-by-design', and their tailored hazard assessment in the context of their potential applications in order to tap the full potential of this versatile material class in the future. [ABSTRACT FROM AUTHOR]

Amine‐functionalized MIL‐101(Cr)‐NH2 metal–organic frameworks (MOF‐N)/epoxy nanocomposites with Excellent cure label and high thermal stability were developed. Structure–property relationship was discussed by comparison of the cure state, thermal and viscoelastic behavior of epoxy nanocomposites containing pristine MOF or MOF‐N applying differential scanning calorimetry (DSC), thermogravimetric analysis, and dynamic mechanical analysis. Epoxy containing 0.3 wt% MOF‐N exhibited high glass transition temperature (Tg) of 96°C compared with 85°C observed for epoxy/MOF system. Thus, MOF‐N played the role of catalyst in epoxy/amine curing reaction. Correspondingly, a lower activation energy was obtained based on cure kinetics modeling based on DSC measurements. Besides, incorporation of low amount (0.5 wt%) MOF‐N induced an early‐state resistance against decomposition, featured by 11°C rise in decomposition temperature at 5% weight loss. This was ascribed to the formation of porous metallic oxides during thermal decomposition of MOF‐N in the epoxy system acting as a heat barrier, which increased the activation energy of decomposition. Amine‐functionalization considerably prevented from further oxidation of the inner part of the matrix. [ABSTRACT FROM AUTHOR]

The potential of safe and low-cost batch production processes for Metal–Organic Frameworks (MOFs) at an industrial scale has been evaluated based on the prototypical MOF MIL-160(Al), a bio-derived material of high practical interest that can be made with a high space-time yield using green ambient pressure conditions. A simple method to calculate the production cost of this material has been determined based on a simulated process constructed with the data collected from laboratory pilot large-scale tests taking into account for the first time in MOF cost evaluation all the process parameters such as the scale, the cost of the raw materials, recirculation, and washing. The investment for a production plant established the ground for the estimation of the complete cost. The expected cost ranged from ca. 55 $ per kg at 100 tons per year down to 29.5 $ per kg for 1 kton per year production with longer term perspectives of reaching costs below 10 $ per kg once the bio-derived ligand is considered for the large-scale production of bioplastics. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs)/graphene oxide (GO) composites are of growing interest due to their properties which can exceed those of the pure components, including post-combustion CO2 capture. Series of composites suitable for CO2 capture under flue gas conditions based on the microporous water stable MIL-91(Ti) have been prepared with different GO contents, following two routes, in situ and post-synthetic. It was observed that the 5 wt% GO in situ composite exhibits a semi-conducting behavior, while the post-synthetic materials are insulating, even with high (20 wt%) GO content. As a consequence, this composite absorbs microwave radiation more efficiently compared to the pure MOF and post-synthetic materials. Finally, we report that CO2 desorption is much faster under microwave irradiation compared to direct electric heating on MOF/GO in situ materials, paving the way for future energy-saving microwave swing adsorption processes. [ABSTRACT FROM AUTHOR]

Room‐temperature syntheses of metal–organic frameworks (MOFs) are of interest to meet the demand of the sustainable chemistry and are a pre‐requisite for the incorporation of functional compounds in water‐stable MOFs. However, only few routes under ambient conditions have been reported to produce metal(IV)‐based MOFs. Reported here is a new versatile one‐step synthesis of a series of highly porous M6‐oxocluster‐based MOFs (M=Zr, Hf, Ce) at room temperature, including 8‐ or 12‐connected micro/mesoporous solids with different functionalized organic ligands. The compounds show varying degrees of defects, particularly for 12‐connected phases, while maintaining the chemical stability of the parent MOFs. Proposed here are first insights into in situ kinetics observations for efficient MOF preparation. Remarkably, the synthesis has a high space‐time yield and also provides the possibility to tune the particle size, therefore paving the way for their practical use. [ABSTRACT FROM AUTHOR]

Room‐temperature syntheses of metal–organic frameworks (MOFs) are of interest to meet the demand of the sustainable chemistry and are a pre‐requisite for the incorporation of functional compounds in water‐stable MOFs. However, only few routes under ambient conditions have been reported to produce metal(IV)‐based MOFs. Reported here is a new versatile one‐step synthesis of a series of highly porous M6‐oxocluster‐based MOFs (M=Zr, Hf, Ce) at room temperature, including 8‐ or 12‐connected micro/mesoporous solids with different functionalized organic ligands. The compounds show varying degrees of defects, particularly for 12‐connected phases, while maintaining the chemical stability of the parent MOFs. Proposed here are first insights into in situ kinetics observations for efficient MOF preparation. Remarkably, the synthesis has a high space‐time yield and also provides the possibility to tune the particle size, therefore paving the way for their practical use. [ABSTRACT FROM AUTHOR]

The 17O resonances of zirconium-oxo clusters that can be found in porous Zr carboxylate metal–organic frameworks (MOFs) have been investigated by magic-angle spinning (MAS) NMR spectroscopy enhanced by dynamic nuclear polarization (DNP). High-resolution 17O spectra at 0.037% natural abundance could be obtained in 48 hours, thanks to DNP enhancement of the 1H polarization by factors ε(1H) = Swith/Swithout = 28, followed by 1H → 17O cross-polarization, allowing a saving in experimental time by a factor of ca. 800. The distinct 17O sites from the oxo-clusters can be resolved at 18.8 T. Their assignment is supported by density functional theory (DFT) calculations of chemical shifts and quadrupolar parameters. Protonation of 17O sites seems to be leading to large characteristic shifts. Hence, natural abundance 17O NMR spectra of diamagnetic MOFs can thus be used to probe and characterize the local environment of different 17O sites on an atomic scale. [ABSTRACT FROM AUTHOR]

Fe(II) coordination complexes have been anchored on robust metal–organic framework secondary building units using a sequential installation strategy. The coordination sphere around Fe(II) was modulated upon sorption of alcohols in the pores of the MOF, leading to a reversible colour change from orange to red. In the case of MFU-4l, a preferential adsorption of MeOH has been observed, evidencing the fact that the host matrix can be used for pre-concentrating a targeted analyte, which may be beneficial for the design of sensing devices. [ABSTRACT FROM AUTHOR]