Chlorination of a Zeolitic-Imidazolate Framework Tunes Packing and van der Waals Interaction of Carbon Dioxide for Optimized Adsorptive Separation.

Molecular separation of carbon dioxide (CO) and methane (CH) is of growing interest for biogas upgrading, carbon capture and utilization, methane synthesis and for purification of natural gas. Here, we report a new zeolitic-imidazolate framework (ZIF), coined COK-17, with exceptionally high affinity for the adsorption of CO by London dispersion forces, mediated by chlorine substituents of the imidazolate linkers. COK-17 is a new type of flexible zeolitic-imidazolate framework Zn(4,5-dichloroimidazolate) with the SOD framework topology.

High-Performance CO-Selective Hybrid Membranes by Exploiting MOF-Breathing Effects.

Conventional CO separation in the petrochemical industry via cryogenic distillation or amine-based absorber-stripper units is energy-intensive and environmentally unfriendly. Membrane-based gas separation technology, in contrast, has contributed significantly to the development of energy-efficient systems for processes such as natural gas purification. The implementation of commercial polymeric membranes in gas separation processes is restricted by their permeability-selectivity trade-off and by their insufficient thermal and chemical stability.

Strategies for Enhancing the Catalytic Performance of Metal-Organic Frameworks in the Fixation of CO into Cyclic Carbonates.

Metal-organic frameworks (MOFs) with accessible Lewis acid sites are finding increasing application in the field of heterogeneous catalysis. However, the structural instability of MOFs when they are exposed to high temperature and/or high pressure often limits their applicability. In this study, two strategies were applied to achieve a MOF catalyst with high stability, activity and selectivity in the reaction of CO with styrene oxide to produce styrene carbonate.

1D-2D-3D Transformation Synthesis of Hierarchical Metal-Organic Framework Adsorbent for Multicomponent Alkane Separation.

A new hierarchical MOF consisting of Cu(II) centers connected by benzene-tricarboxylates (BTC) is prepared by thermoinduced solid transformation of a dense CuBTC precursor phase. The mechanism of the material formation has been thoroughly elucidated and revealed a transformation of a ribbon-like 1D building unit into 2D layers and finally a 3D network. The new phase contains excess copper, charge compensated by systematic hydroxyl groups, which leads to an open microporous framework with tunable permanent mesoporosity.

Polymer supported ZIF-8 membranes prepared via an interfacial synthesis method.

Porous polymer supported continuous ZIF-8 membranes were prepared via an interfacial synthesis method. Membranes with only one synthesis cycle showed excellent performance in the nanofiltration range.

Local transformation of ZIF-8 powders and coatings into ZnO nanorods for photocatalytic application.

Silver nitrate induces spontaneous room temperature transformation of ZIF-8 into a composite of ZnO nanorods embedded in a ZIF-8 matrix. This first example of reverse transformation of ZIF-8 into ZnO is a convenient method for generating fixed ZnO nanoparticles in powders as well as films and coatings. The fabricated ZnO nanorod@ZIF-8 is photocatalytically active.

Copper benzene tricarboxylate metal-organic framework with wide permanent mesopores stabilized by Keggin polyoxometallate ions.

Porous solids with organized multiple porosity are of scientific and technological importance for broadening the application range from traditional areas of catalysis and adsorption/separation to drug release and biomedical imaging. Synthesis of crystalline porous materials offering a network of uniform micro- and mesopores remains a major scientific challenge. One strategy is based on variation of synthesis parameters of microporous networks, such as, for example, zeolites or metal-organic frameworks (MOFs).

Convenient synthesis of Cu3(BTC)2 encapsulated Keggin heteropolyacid nanomaterial for application in catalysis.

Nanomaterial of Cu(3)(BTC)(2) (BTC = benzene tricarboxylic acid) incorporating Keggin heteropolyacid conveniently prepared at room temperature and recovered by freeze drying outperforms ultrastable Y zeolite in acid catalysed esterification reaction.