Porous Organic Polymers for Efficient and Selective SO Capture from CO-rich Flue Gas.

The quest for effective technologies to reduce SO pollution is crucial due to its adverse effects on the environment and human health. Markedly, removing a ppm level of SO from CO-containing waste gas is a persistent challenge, and current technologies suffer from low SO/CO selectivity and energy-intensive regeneration processes. Here using the molecular building blocks approach and theoretical calculation, we constructed two porous organic polymers (POPs) encompassing pocket-like structures with exposed imidazole groups, promoting preferential interactions with SO from CO-containing streams.

Enabling simultaneous valorization of tannery effluent and waste plastic via sustainable preparation of Cr-BDC MOFs for water adsorption.

Advanced materials undergo a complex and lengthy process of maturation for scaling up and deployment, mainly due to the high cost of their precursors. Therefore, it is highly desirable to fabricate highly valuable advanced porous solid-state materials, with proven applicability, by sustainably combining organic and inorganic waste materials as precursors. This study successfully demonstrates the preparation of Cr-terephthalate Metal-Organic Frameworks (Cr-BDC MOFs) by combining metal salt and organic linker extracted from tannery effluent and waste plastic bottles.

ZIF-62 glass foam self-supported membranes to address CH/N separations.

Membranes with ultrahigh permeance and practical selectivity could greatly decrease the cost of difficult industrial gas separations, such as CH/N separation. Advanced membranes made from porous materials, such as metal-organic frameworks, can achieve a good gas separation performance, although they are typically formed on support layers or mixed with polymeric matrices, placing limitations on gas permeance. Here an amorphous glass foam, aZIF-62, wherein a, g and f denote amorphous, glass and foam, respectively, was synthesized by a polymer-thermal-decomposition-assisted melting strategy, starting from a crystalline zeolitic imidazolate framework, ZIF-62.

A Zeolite-Like Metal-Organic Framework Based Membrane for Reverse Selective Hydrogen Separation and Butane Isomer Sieving.

Here, the fabrication of a defect-free membrane that is based on a zeolite-like metal-organic framework (ZMOF) with the underlying ana topology is reported. The unique ana-ZMOF structure provides high degree of pore connectivity, which is reflected by the fast transport of gases. Prominently, it offers an optimum pore-aperture size, affording notable sieving selectivity for butane/isobutane, and optimal pore energetics for reverse CO /H separation.

Reticular Chemistry for the Construction of Highly Porous Aluminum-Based -Metal-Organic Frameworks.

Edge-transitive nets are regarded as appropriate blueprints for the practice of reticular chemistry, and in particular, for the rational design and synthesis of functional metal-organic frameworks (MOFs). Among edge-transitive nets, type I edge-transitive nets have unique coordination figures, offering only one edge-transitive target for their associated expressed -cBUs. Here, we report the reticulation of the binodal edge-transitive (6, 6)-c net in MOF chemistry, namely, the deliberate assembly of trinuclear aluminum clusters and 6-connected hexacarboxylate ligands into highly porous -MOFs.

Differential guest location by host dynamics enhances propylene/propane separation in a metal-organic framework.

Energy-efficient approaches to propylene/propane separation such as molecular sieving are of considerable importance for the petrochemical industry. The metal organic framework NbOFFIVE-1-Ni adsorbs propylene but not propane at room temperature and atmospheric pressure, whereas the isostructural SIFSIX-3-Ni does not exclude propane under the same conditions. The static dimensions of the pore openings of both materials are too small to admit either guest, signalling the importance of host dynamics for guest entrance to and transport through the channels.

Quest for an Optimal Methane Hydrate Formation in the Pores of Hydrolytically Stable Metal-Organic Frameworks.

Porous metal-organic frameworks (MOFs) capable of storing a relatively high amount of dry methane (CH) in the adsorbed phase are largely explored; however, solid CH storage in confined pores of MOFs in the form of hydrates is yet to be discovered. Here we report a rational approach to form CH hydrates by taking advantage of the optimal pore confinement in relatively narrow cavities of hydrolytically stable MOFs. Unprecedentedly, we were able to isolate methane hydrate (MH) nanocrystals with an sI structure encapsulated inside MOF pores with an optimal cavity dimension.

Made-to-order porous electrodes for supercapacitors: MOFs embedded with redox-active centers as a case study.

In this work, a pre-designed Zr-based-MOF encompassing an organic linker with a redox active core is synthesized and its structure-property relationship as a supercapacitor electrode is investigated. An enhanced performance is revealed by the combination of this MOF's high porosity and redox core incorporation, which alters its double-layer and pseudocapacitance, respectively. An increase in the capacitance performance by a factor of two is achieved via post-synthetic structure rigidification using organic pillars.

Revisiting the water sorption isotherm of MOF using electrical measurements.

Water adsorption/desorption isotherms of Cr-soc-MOF-1 were monitored electrically, with the translation of proton conductivity measurements to physisorption isotherms in terms of S-shape and hysteresis features revealed by volumetry. Molecular modelling further established the relationship between the evolutive water-hydrogen bonded network and the "electrical" isotherm for this water-mediated proton conducting MOF.

Imaging defects and their evolution in a metal-organic framework at sub-unit-cell resolution.

Defect engineering of metal-organic frameworks (MOFs) offers promising opportunities for tailoring their properties to specific functions and applications. However, determining the structures of defects in MOFs-either point defects or extended ones-has proved challenging owing to the difficulty of directly probing local structures in these typically fragile crystals. Here we report the real-space observation, with sub-unit-cell resolution, of structural defects in the catalytic MOF UiO-66 using a combination of low-dose transmission electron microscopy and electron crystallography.

Conformation-Controlled Molecular Sieving Effects for Membrane-Based Propylene/Propane Separation.

Membrane-based separation is poised to reduce the operation cost of propylene/propane separation; however, identifying a suitable molecular sieve for membrane development is still an ongoing challenge. Here, the successful identification and use of a metal-organic framework (MOF) material as fillers, namely, the Zr-fum-fcu-MOF possessing an optimal contracted triangular pore-aperture driving the efficient diffusive separation of propylene from propane in mixed-matrix membranes are reported. It is demonstrated that the fabricated hybrid membranes display a high propylene/propane separation performance, far beyond the current trade-off limit of polymer membranes with excellent properties under industrial conditions.

Polyoxometalate-Cyclodextrin Metal-Organic Frameworks: From Tunable Structure to Customized Storage Functionality.

Self-assembly allows structures to organize themselves into regular patterns by using local forces to find the lowest-energy configuration. However, assembling organic and inorganic building blocks in an ordered framework remains challenging due to  difficulties in rationally interfacing two dissimilar materials. Herein, the ensemble of polyoxometalates (POMs) and cyclodextrins (CDs) as molecular building blocks (MBBs) has yielded two unprecedented POM-CD-MOFs, namely [PWO] and α-CD MOF (POT-CD) as well as [PPdO] and γ-CD MOF (POP-CD), with distinct properties not shared by their isolated parent MBBs.

Concurrent Sensing of CO and HO from Air Using Ultramicroporous Fluorinated Metal-Organic Frameworks: Effect of Transduction Mechanism on the Sensing Performance.

Conventional materials for gas/vapor sensing are limited to a single probe detection ability for specific analytes. However, materials capable of concurrent detection of two different probes in their respective harmful levels and using two types of sensing modes have yet to be explored. In particular, the concurrent detection of uncomfortable humidity levels and CO concentration (400-5000 ppm) in confined spaces is of extreme importance in a great variety of fields, such as submarine technology, aerospace, mining, and rescue operations.

Publisher Correction: Mixed matrix formulations with MOF molecular sieving for key energy-intensive separations.

In the version of this Article originally published, the units of the y axis of Fig. 3b were incorrectly given as '10 cm s'; they should have been '10 cm s'. This has been corrected in the online versions of the Article.

Enhanced Separation of Butane Isomers via Defect Control in a Fumarate/Zirconium-Based Metal Organic Framework.

The discovery of appropriate synthetic reaction conditions for fabricating a stable zirconium-based molecular sieve (Zr-fum-fcu-MOF) with minimal defects and its utilization in the challenging separation of linear paraffins from branched paraffins is reported. The crystallinity and structural defects were modulated and adjusted at the molecular level by controlling the synthetic reaction conditions (i.e.

Enhanced CO/CH Separation Performance of a Mixed Matrix Membrane Based on Tailored MOF-Polymer Formulations.

Membrane-based separations offer great potential for more sustainable and economical natural gas upgrading. Systematic studies of CO/CH separation over a wide range of temperatures from 65 °C (338 K) to as low as -40 °C (233 K) reveals a favorable separation mechanism toward CO by incorporating Y---MOF as a filler in a 6FDA-DAM polyimide membrane. Notably, the decrease of the temperature from 308 K down to 233 K affords an extremely high CO/CH selectivity (≈130) for the hybrid Y---MOF/6FDA-DAM membrane, about four-fold enhancement, with an associated CO permeability above 1000 barrers.

Enabling Fluorinated MOF-Based Membranes for Simultaneous Removal of H S and CO from Natural Gas.

Membrane-based gas separations are energy efficient processes; however, major challenges remain to develop high-performance membranes enabling the replacement of conventional separation processes. Herein, a new fluorinated MOF-based mixed-matrix membrane is reported, which is formed by incorporating the MOF crystals into selected polymers via a facile mixed-matrix approach. By finely controlling the molecular transport in the channels through the MOF apertures tuned by metal pillars and at the MOF-polymer interfaces, the resulting fluorinated MOF-based membranes exhibit excellent molecular sieving properties.

Achieving Superprotonic Conduction with a 2D Fluorinated Metal-Organic Framework.

A hydrolytically stable metal-organic framework (MOF) material, named KAUST-7', was derived from a structural phase change of KAUST-7 upon exposure to conditions akin to protonic conduction (363 K/95% relative humidity). KAUST 7' exhibited a superprotonic conductivity as evidenced by the impedance spectroscopic measurement revealing an exceptional conductivity up to 2.0 × 10 S cm at 363 K and under 95% RH, a performance maintained over 7 days.

Upgrading gasoline to high octane numbers using a zeolite-like metal-organic framework molecular sieve with ana-topology.

Separation of paraffin isomers is of great importance in the refining industry because of their potential applications for energy efficiency, as reflected by their associated Research Octane Number (RON) values. Here, we report the synthesis of the first zeolite-like metal-organic framework (ZMOF) with ana topology that displays helicoidally/cylindrically-shaped channels with a pore-aperture size of ca. 3.

Enriching the Reticular Chemistry Repertoire: Merged Nets Approach for the Rational Design of Intricate Mixed-Linker Metal-Organic Framework Platforms.

Rational design and construction of metal-organic frameworks (MOFs) with intricate structural complexity are of prime importance in reticular chemistry. We report our latest addition to the design toolbox in reticular chemistry, namely the concept of merged nets based on merging two edge-transitive nets into a minimal edge-transitive net for the rational construction of intricate mixed-linker MOFs. In essence, a valuable net for design enclosing two edges (not related by symmetry) is rationally generated by merging two edge-transitive nets, namely (3,6)-coordinated spn and 6-coordinated hxg.

Correction: Topology meets MOF chemistry for pore-aperture fine tuning: ftw-MOF platform for energy-efficient separations via adsorption kinetics or molecular sieving.

Correction for 'Topology meets MOF chemistry for pore-aperture fine tuning: ftw-MOF platform for energy-efficient separations via adsorption kinetics or molecular sieving' by Dong-Xu Xue et al., Chem. Commun.

Topology meets MOF chemistry for pore-aperture fine tuning: ftw-MOF platform for energy-efficient separations via adsorption kinetics or molecular sieving.

Herein we demonstrate how the combined use of the molecular building block (MBB) approach and reticular chemistry allows the fabrication of a highly stable, ultra-microporous metal-organic framework (MOF) that is an efficient sorbent for the challenging separation of propane/propylene.

Nanosheets of Nonlayered Aluminum Metal-Organic Frameworks through a Surfactant-Assisted Method.

During the last decade, the synthesis and application of metal-organic framework (MOF) nanosheets has received growing interest, showing unique performances for different technological applications. Despite the potential of this type of nanolamellar materials, the synthetic routes developed so far are restricted to MOFs possessing layered structures, limiting further development in this field. Here, a bottom-up surfactant-assisted synthetic approach is presented for the fabrication of nanosheets of various nonlayered MOFs, broadening the scope of MOF nanosheets application.

Mixed matrix formulations with MOF molecular sieving for key energy-intensive separations.

Membrane-based separations can improve energy efficiency and reduce the environmental impacts associated with traditional approaches. Nevertheless, many challenges must be overcome to design membranes that can replace conventional gas separation processes. Here, we report on the incorporation of engineered submicrometre-sized metal-organic framework (MOF) crystals into polymers to form hybrid materials that successfully translate the excellent molecular sieving properties of face-centred cubic (fcu)-MOFs into the resultant membranes.