separation of acetylene and ethylene is an important industrial process because both compounds are essential reagents for a range of chemical products and materials. Current separation approaches include the partial hydrogenation of acetylene into ethylene over a supported Pd catalyst, and the extraction of cracked olefins using an organic solvent; both routes are costly and energy consuming. Adsorption technologies may allow separation, but microporous materials exhibiting highly selective adsorption of C 2 H 2 /C 2 H 4 have not been realized to date. Here, we report the development of tunable microporous enantiopure mixed-
Four porous isostructural mixed-metal-organic frameworks (M'MOFs) have been synthesized and structurally characterized. The pores within these M'MOFs are systematically tuned by the interplay of both the metalloligands and organic ligands which have enabled us not only to direct their highly selective separation of chiral alcohols 1-phenylethanol (PEA), 2-butanol (BUT), and 2-pentanol (2-PEN) with the highest ee up to 82.4% but also to lead highly selective separation of achiral C(2)H(2)/C(2)H(4) separation. The potential application of these M'MOFs for the fixed bed pressure swing adsorption (PSA) separation of C(2)H(2)/C(2)H(4) has been further examined and compared by the transient breakthrough simulations in which the purity requirement of 40 ppm in the outlet gas can be readily fulfilled by the fixed bed M'MOF-4a adsorber at ambient conditions.
Immobilization of functional sites within metal-organic frameworks (MOFs) is very important for their ability to recognize small molecules and thus for their functional properties. The metalloligand approach has enabled us to rationally immobilize a variety of different functional sites such as open metal sites, catalytic active metal sites, photoactive metal sites, chiral pore environments, and pores of tunable sizes and curvatures into mixed metal-organic frameworks (M'MOFs). In this Minireview, we highlight some important functional M'MOFs with metalloligands for gas storage and separation, enantioselective separation, heterogeneous asymmetric catalysis, sensing, and as photoactive and nanoscale drug delivery and biomedical imaging materials.
A doubly interpenetrated semiconducting MOF Zn(4)O(2,6-NDC)(3)(DMF)(1.5)(H(2)O)(0.5)·4DMF·7.5H(2)O (UTSA-38) of a cubic net has been constructed, which exhibits photocatalytic activity for the degradation of methyl orange in aqueous solution.
The proton‐exchange membrane (PEM) is a fundamental module of proton‐exchange membrane fuel cells (PEMFCs), permitting proton passage and thus governing the overall performance of PEMFCs. Till now, Nafion has been the extensively used marketable PEM material due to its high protonic conductivity of 10−2–10−1 S cm−1 under high relative humidity and 80–85 °C. On the other hand, crystalline materials such as metal‐organic frameworks (MOFs), coordination polymers (CPs), covalent organic frameworks (COFs), hydrogen‐bonded organic framework (HOFs), metalo hydrogen‐bonded organic framework (MHOFs), and polyoxometalates (POMs) are emerging as potential PEM materials, where crystallinity has paved the way to study the conduction pathway and associated mechanisms to understand structure‐function relationships. However, to date, ultrahigh superprotonic conductivity to the level of 10−1 S cm−1, close to Nafion, is relatively scarce for the crystalline proton conductors. In this review, the discussion is focused on materials that demonstrate a conductivity order of 10−1 S cm−1 and higher for those individual crystalline platforms (to be on the equal footing and superior to nafion, respectively) based on their synthesis approach while highlighting the design norms and key features for attaining such ultrahigh conductivity. While a critical analysis is made, the key issues and future prospects are also addressed.
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