Author
Nakeun Ko
Bio: Nakeun Ko is an academic researcher from Soongsil University. The author has contributed to research in topics: Adsorption & Metal-organic framework. The author has an hindex of 10, co-authored 16 publications receiving 3722 citations.
Papers
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TL;DR: The synthesis of a MOF in which zinc centers are bridged with long, highly conjugated organic linkers, but in which the overall symmetry of the networks created prevents formation of interpenetrating networks is described.
Abstract: Crystalline solids with extended non-interpenetrating three-dimensional crystal structures were synthesized that support well-defined pores with internal diameters of up to 48 angstroms The Zn4O(CO2)6 unit was joined with either one or two kinds of organic link, 4,4',4''-[benzene-1,3,5-triyl-tris(ethyne-2,1-diyl)]tribenzoate (BTE), 4,4',44''-[benzene-1,3,5-triyl-tris(benzene-4,1-diyl)]tribenzoate (BBC), 4,4',44''-benzene-1,3,5-triyl-tribenzoate (BTB)/2,6-naphthalenedicarboxylate (NDC), and BTE/biphenyl-4,4'-dicarboxylate (BPDC), to give four metal-organic frameworks (MOFs), MOF-180, -200, -205, and -210, respectively Members of this series of MOFs show exceptional porosities and gas (hydrogen, methane, and carbon dioxide) uptake capacities For example, MOF-210 has Brunauer-Emmett-Teller and Langmuir surface areas of 6240 and 10,400 square meters per gram, respectively, and a total carbon dioxide storage capacity of 2870 milligrams per gram The volume-specific internal surface area of MOF-210 (2060 square meters per cubic centimeter) is equivalent to the outer surface of nanoparticles (3-nanometer cubes) and near the ultimate adsorption limit for solid materials
3,189 citations
TL;DR: Three new MOFs that are isoreticular expansions of known materials with the tbo and pto topologies are described, including one that has the highest porosity and lowest density of any MOFs reported to date.
Abstract: The concept and occurrence of isoreticular (same topology) series of metal–organic frameworks (MOFs) is reviewed. We describe the preparation, characterization, and crystal structures of three new MOFs that are isoreticular expansions of known materials with the tbo (Cu3(4,4′,4″-(benzene-1,3,5-triyl-tris(benzene-4,1-diyl))tribenzoate)2, MOF-399) and pto topologies (Cu3(4,4′,4″-(benzene-1,3,5-triyl-tribenzoate)2, MOF-143; Cu3(4,4′,4″-(triazine-2,4,6-triyl-tris(benzene-4,1-diyl))tribenzoate)2, MOF-388). One of these materials (MOF-399) has a unit cell volume 17 times larger than that of the first reported material isoreticular to it, and has the highest porosity (94%) and lowest density (0.126 g cm–3) of any MOFs reported to date.
321 citations
TL;DR: It is found that the position of the functional groups on the BTB unit allows the selection for a specific net (qom, pyr, and rtl), and that mixing of functionalities is an important strategy for the incorporation of a specific functionality into MOF-177 where otherwise incorporation of such functionality would be difficult.
Abstract: Metal-organic framework-177 (MOF-177) is one of the most porous materials whose structure is composed of octahedral Zn4O(-COO)6 and triangular 1,3,5-benzenetribenzoate (BTB) units to make a three-dimensional extended network based on the qom topology. This topology violates a long-standing thesis where highly symmetric building units are expected to yield highly symmetric networks. In the case of octahedron and triangle combinations, MOFs based on pyrite (pyr) and rutile (rtl) nets were expected instead of qom. In this study, we have made 24 MOF-177 structures with different functional groups on the triangular BTB linker, having one or more functionalities. We find that the position of the functional groups on the BTB unit allows the selection for a specific net (qom, pyr, and rtl), and that mixing of functionalities (-H, -NH2, and -C4H4) is an important strategy for the incorporation of a specific functionality (-NO2) into MOF-177 where otherwise incorporation of such functionality would be difficult. Such mixing of functionalities to make multivariate MOF-177 structures leads to enhancement of hydrogen uptake by 25%.
320 citations
TL;DR: The selective sorption of acetylene over carbon dioxide and ethylene in JCM-1 was successfully demonstrated by equilibrium gas adsorption analysis as well as dynamic breakthrough measurement and its excellent hydrolytic stability makes the separation processes highly recyclable without a substantial loss in acetylene uptake capacity.
Abstract: Separation of acetylene from carbon dioxide and ethylene is challenging in view of their similar sizes and physical properties. Metal-organic frameworks (MOFs) in general are strong candidates for these separations owing to the presence of functional pore surfaces that can selectively capture a specific target molecule. Here, we report a novel 3D microporous cationic framework named JCM-1. This structure possesses imidazolium functional groups on the pore surfaces and pyrazolate as a metal binding group, which is well known to form strong metal-to-ligand bonds. The selective sorption of acetylene over carbon dioxide and ethylene in JCM-1 was successfully demonstrated by equilibrium gas adsorption analysis as well as dynamic breakthrough measurement. Furthermore, its excellent hydrolytic stability makes the separation processes highly recyclable without a substantial loss in acetylene uptake capacity.
183 citations
TL;DR: The functionalization of UiO-67 with -NH2 groups enhances CO2 and CH4 adsorption at 1 bar and 298 K and positively influences the framework's interaction with water as evidenced by the significant enhancement of water vapour adsorbed at 0.1 < P/P0 < 0.3.
Abstract: The functionalization of UiO-67 with -NH2 groups enhances CO2 and CH4 adsorption at 1 bar and 298 K and positively influences the framework's interaction with water as evidenced by the significant enhancement of water vapour adsorption at 0.1 < P/P0 < 0.3 and 298 K.
103 citations
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TL;DR: Metal-organic frameworks are porous materials that have potential for applications such as gas storage and separation, as well as catalysis, and methods are being developed for making nanocrystals and supercrystals of MOFs for their incorporation into devices.
Abstract: Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.
10,934 citations
5,393 citations
TL;DR: Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long
Abstract: Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long
5,389 citations
3,087 citations
2,568 citations