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Separation of hydrocarbon mixtures into single components is a very important industrial process because all represent very important energy resources/raw chemicals in the petrochemical industry. The well-established industrial separation technology highly relies on the energy-intensive cryogenic distillation processes. The discovery of new materials capable of separating hydrocarbon mixtures by adsorbent-based separation technologies has the potential to provide more energy-efficient industrial processes with remarkable energy savings. Porous metal-organic frameworks (MOFs), also known as porous coordination polymers, represent a new class of porous materials that offer tremendous promise for hydrocarbon separations because of their easy tunability, designability, and functionality. A number of MOFs have been designed and synthesized to show excellent separation performance on various hydrocarbon separations. Here, we summarize and highlight some recent significant advances in the development of microporous MOFs for hydrocarbon separation applications.

Good biocompatibility, active tumor targeting, and stimulus-responsive release offer great opportunity for precise imaging-guided tumor treatment. However, the current strategies for the fabrication of smart theranostic platforms suffer from tedious synthesis processes. Here, we propose a universal and facile strategy for the fabrication of smart nanoscale metal-organic framework (NMOF)-based nanoplatforms for imaging-guided precise chemotherapy. As a proof of concept, 5-boronobenzene-1,3-dicarboxylic acid (BBDC), as a versatile ligand, was employed for the first time with Gd 3+ as metal nodes to prepare a smart magnetic resonance (MR) imaging-guided drug-delivery system. Specific reversible diol-borate condensation enables effortless coating of glucose on the NMOFs to improve their biocompatibility. The specific interaction between glucose and glucose-transported protein ensures active tumor-targeting ability. Moreover, the glucose layer, as a pH-responsive diol-borate gatekeeper, prevents the premature leakage of drugs. The proposed smart theranostic nanoplatform was well used in MR imaging-guided tumor-targeted precise chemotherapy. This strategy is simply extended to the design of other MOF-glucose composites for diverse applications, such as X-ray computed tomography imaging of gastrointestinal tract with Yb-MOFs-Glu. BBDC, as a functional ligand, provides a simple and universal way to fabricate smart NMOF theranostic platforms with multifunction as "three birds with one stone". The facile and universal strategy lays down a new way to develop multifunctional nanoagents for precision medicine.

Developing porous materials to overcome the trade‐off between adsorption capacity and selectivity for C2H2/CO2 separation remains a challenge. Herein, we report a stable HKUST‐1‐like MOF (ZJU‐50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2H2 storage and selectivity. ZJU‐50a exhibits one of the highest C2H2 storage capacity (192 cm3 g−1) and concurrently high C2H2/CO2 selectivity (12) at 298 K and 1 bar. Single‐crystal X‐ray diffraction studies on gas‐loaded ZJU‐50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2H2 molecule but not CO2 to result in both high C2H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2H2/CO2 mixtures, providing a high C2H2 recovery capacity of 84.2 L kg−1 with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade‐off for this separation. [ABSTRACT FROM AUTHOR]

The realization of ideal molecular sieves has a great potential to achieve the desired gas separations by fine‐tuning pore structures to generate suitable aperture sizes, which can be exclusive to larger molecules thus performing efficient separations. Despite numerous attempts, there are few developed porous materials that implement molecular sieving for C2H2/CH4 separation. Herein, we show how fine‐tuning of pore size in a series of selected SIFSIX materials achieves ideal molecular sieving for C2H2/CH4 separation at ambient conditions. With an optimized pore size of 3.4 Å and abundant binding sites in the channels, UTSA‐200 shows complete exclusion of larger CH4 molecules, while maintaining strong affinities toward C2H2. Therefore, this material exhibits both high uptake capacity at low pressure (up to 41 cm3 g−1 at 0.01 bar and 296 K) and record C2H2/CH4 selectivity (over 1×107). Dynamic breakthrough experiments validated the ideal sieving separation performance of UTSA‐200 for C2H2/CH4 mixtures, affording an exceptionally high C2H2 capacity of 73.5 L kg−1 with high purity of 99.5 % per cycle. [ABSTRACT FROM AUTHOR]

Developing efficient and stable water adsorbents for adsorption‐driven heat transfer technology still remains a challenge due to the lack of efficient strategies to enhance low‐pressure water uptakes. The authors herein demonstrate that the immobilization of Lewis basic nitrogen sites into metal–organic frameworks (MOFs) can improve water uptake and target benchmark coefficient of performances (COPs) for cooling and heating. They present the water sorption properties of a chemically stable MOF (termed as Zr‐adip), designed by incorporating hydrophilic nitrogen sites into the adsorbent MIP‐200. Zr‐adip exhibits S‐shaped sorption isotherms with an extremely high water uptake of 0.43 g g−1 at 303 K and P/P0 = 0.25, higher than MIP‐200 (0.39 g g−1), KMF‐1 (0.39 g g−1) and MOF‐303 (0.38 g g−1). Theoretical calculations reveal that the incorporated N sites can serve as secondary adsorption sites to moderately interact with water, providing more binding sites to strengthen the water binding affinity. Zr‐adip achieves exceptionally high COPs of 0.79 (cooling) and 1.75 (heating) with a low driving temperature of 70 °C, outperforming MIP‐200 (0.78 and 1.53) and KMF‐1 (0.75 and 1.74). Combined with its ultrahigh stability, excellent cycling performance, and easy regeneration, Zr‐adip represents one of the best water adsorbents for adsorption‐driven cooling and heating. [ABSTRACT FROM AUTHOR]

Separation of acetylene from carbon dioxide remains a daunting challenge because of their very similar molecular sizes and physical properties. We herein report the first example of using copper(I)‐alkynyl chemistry within an ultra‐microporous MOF (CuI@UiO‐66‐(COOH)2) to achieve ultrahigh C2H2/CO2 separation selectivity. The anchored CuI ions on the pore surfaces can specifically and strongly interact with C2H2 molecule through copper(I)‐alkynyl π‐complexation and thus rapidly adsorb large amount of C2H2 at low‐pressure region, while effectively reduce CO2 uptake due to the small pore sizes. This material thus exhibits the record high C2H2/CO2 selectivity of 185 at ambient conditions, significantly higher than the previous benchmark ZJU‐74a (36.5) and ATC‐Cu (53.6). Theoretical calculations reveal that the unique π‐complexation between CuI and C2H2 mainly contributes to the ultra‐strong C2H2 binding affinity and record selectivity. The exceptional separation performance was evidenced by breakthrough experiments for C2H2/CO2 gas mixtures. This work suggests a new perspective to functionalizing MOFs with copper(I)‐alkynyl chemistry for highly selective separation of C2H2 over CO2. [ABSTRACT FROM AUTHOR]

A novel expanded metal–organic framework (UTSA-111a) with functional pyrimidine sites exhibits simultaneously high gravimetric and volumetric methane storage working capacities of 309 cm3 (STP) g−1 and 183 cm3 (STP) cm−3 at 298 K and 5.8–65 bar. [ABSTRACT FROM AUTHOR]

The development of new materials for separating ethylene (C2H4) from ethane (C2H6) by adsorption is of great importance in the petrochemical industry, but remains very challenging owing to their close molecular sizes and physical properties. Using isoreticular chemistry in metal–organic frameworks (MOFs) enables the precise design and construction of target materials with suitable aperture sizes and functional sites for gas separations. Herein, it is described that fine‐tuning of pore size and π‐complexation simultaneously in microporous copper(I)‐chelated MOFs can remarkably boost the C2H4/C2H6 adsorption selectivity. The judicious choice of organic linkers with a different number of carboxyl groups in the UiO‐66 framework not only allows the fine tuning of the pore size but also immobilizes copper(I) ions onto the framework. The tailor‐made adsorbent, CuI@UiO‐66‐(COOH)2, thus possesses the optimal pore window size and chelated Cu(I) ions to form π‐complexation with C2H4 molecules. It can rapidly adsorb C2H4 driven by the strong π‐complexation interactions, while effectively reducing C2H6 uptake due to the selective size‐sieving. Therefore, this material exhibits an ultrahigh C2H4/C2H6 selectivity (80.8), outperforming most previously described benchmark materials. The exceptional separation performance of CuI@UiO‐66‐(COOH)2 is validated by breakthrough experiments for 50/50 v/v C2H4/C2H6 mixtures under ambient conditions. [ABSTRACT FROM AUTHOR]

Cd2+ sensors play an essential role in biology and environment. We adopted the post-modification and interfacial polymerization strategies to realize a free-standing and homogeneous filmy Cd2+ electrochemical sensor by copolymerizing MOF-867 nanocrystals with pyrrole monomers. This hybrid film exhibited good structural integrity and retained Cd2+ sensing behavior with good conductivity in a covalent film form. This poly-MOF hybrid film exhibited a highly excellent sensing selectivity and sensitivity for Cd2+ with a very low detection limit around 0.29 μg L−1, lower than pure MOF-867 and significantly below the standard for Cd2+ in drinking water, which benefited from the devisable architectures of MOF-867 with the good conductivity of PPy polymer matrix. This work highlighted a simple strategy for poly-MOF film formation and accelerated the MOFs-based materials for Cd2+ electrochemical sensing in practical applications. In this work, we presented a MOFs@PPy composite film prepared by covalently embedding MOFs into the surface of PPy films. And this hybrid film exhibited excellent Cd2+ electrochemical sensing behavior. [Display omitted] • A conductive poly-MOF free-standing and homogeneous filmy electrochemical sensor. • This MOFs-based hybrid film exhibited high sensory performances to Cd2+. • A simple strategy for fabricating chemical bonds between MOFs particles and polymers. [ABSTRACT FROM AUTHOR]

NO2− sensing is closely associated with human health, and we adopted lanthanide Eu3+ post‐modified MOF as NO2− fluorescent probes. Typical stable MOF with uncoordinated carboxylic groups in the framework were chosen to encapsulate Eu3+. NO2− could generate an obvious quenching response to the fluorescence intensity. This Eu3+ functionalized MOF exhibited excellent fluorescence performances and obvious quenching response to NO2− based on the energy transfer between Eu3+ and NO2−. This MOF based NO2− fluorescent probe showed a highly splendid detection selectivity and sensitivity with a very low detection limit of 0.69 μM, which was significantly below the maximal level limits of NO2− in drinking water set by the WHO. [ABSTRACT FROM AUTHOR]