Mn-based Metal-organic Frameworks Research Articles

Rod-like carbon-coated MnS derived from metal-organic frameworks as high-performance anode material for sodium-ion batteries

A novel rod-like carbon-coated MnS electrode material (MnS/C) hybrid for sodium ions batteries (SIBs) was designed by annealing Mn-based metal-organic frameworks coupled with sulfur. When evaluated as anode material for SIBs, the typical MnS/C hybrid exhibits satisfied reversible capacity of 297 mAh g−1 after 100 cycles at 50 mA g−1, excellent rate capability (173.9 mAh g−1 at 1 A g−1 and 143.1 mAh g−1 at 2.5 A g−1) and robust long-term cycling stability (148.3 mAh g−1 after 5000 cycles at 1 A g−1), showing great potential for high-performance SIBs.

A Metal-Organic Framework with Exceptional Activity for C-H Bond Amination.

The development of catalysts capable of fast, robust C-H bond amination under mild conditions is an unrealized goal despite substantial progress in the field of C-H activation in recent years. A Mn-based metal-organic framework (CPF-5) is described that promotes the direct amination of C-H bonds with exceptional activity. CPF-5 is capable of functionalizing C-H bonds in an intermolecular fashion with unrivaled catalytic stability producing >105 turnovers.

Mesoporous MnO/C-N Nanostructures Derived from a Metal-Organic Framework as High-Performance Anode for Lithium-Ion Battery.

By application of newly designed ligand 5-(3-(pyridin-3-yl)benzamido)isophthalic acid (H2PBI) to react with Mn(NO3)2 under solvothermal conditions, a 2-fold interpenetrated Mn-based metal-organic framework (Mn-PBI) with rutile-type topology has been obtained. When treated as a precursor by pyrolysis of Mn-PBI at 500 °C, mesoporous MnO/C-N nanostructures were prepared and treated as an lithium-ion battery anode. The MnO/C-N manifests good capacity of approximately 1085 mAh g-1 after 100 cycles together with superior cyclic stability and remarkable rate capacity, which is supposed to benefit from a large accessible specific area and unique nanostructures. The remarkable performances suggest promising application as an advanced anode material.

MnO@C nanorods derived from metal-organic frameworks as anode for superiorly stable and long-life sodium-ion batteries

Abstract Porous MnO@C nanorods were synthesized simply by annealing Mn-based metal-organic frameworks precursor. The morphology, structure and electrochemical performance of MnO@C hybrid were characterized by scanning electron microscopy, nitrogen adsorption/desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impendence spectroscopy. When used as anode material for sodium-ion batteries, the MnO@C hybrid exhibits a high reversible specific capacity of 260 mAh g −1 after 100 cycles at a current density of 50 mA g −1 . When the current density is increased to 2 A g −1 , the MnO@C delivers a superior long-life cycling performance with a capacity of 140 mAh g −1 at very high current density of 2 A g −1 . The excellent electrochemical performance of MnO@C can be attributed to its unique porous structure with MnO nanoparticles embedded in carbon matrix, which can apparently increase the electrical conductivity and buffer the volume change during the charge/discharge process.

Liquid-phase oxidation of alkylaromatics to aromatic ketones with molecular oxygen over a Mn-based metal-organic framework.

Liquid-phase oxidation of alkylaromatics with molecular O2 was examined using a microporous Mn-based metal-organic framework (Mn-MOF-74). Mn-MOF-74 consisting of trimeric Mn clusters and 2,5-dihydroxyterephthalate (dhtp) linkers exhibits superior catalytic activity with good ketone selectivity compared to conventional oxide-supported Mn catalysts without showing any lengthy induction period. Combined analyses by means of XRD, FE-SEM, N2 physisorption and Mn K-edge XAFS reveal that the superior catalytic performance is attributed to the inherently-formed Mn(iii)2(dhtp) moieties embedded in the Mn-MOF-74 framework rather than structural factors associated with the MOF. The catalyst is reusable over multiple catalytic runs along with retaining its original catalytic activity due to the ability of the dhtp ligand to stabilize active Mn(iii) atoms. Owing to high activity, reusability and nontoxicity, Mn-MOF-74 can offer a simple, inexpensive and efficient protocol for the oxidation of some important alkylaromatics, such as ethylbenzene and diphenylmethane to produce the corresponding aromatic ketones.

Layered manganese-based metal–organic framework as a high capacity electrode material for supercapacitors

The layered Mn-based metal–organic framework (Mn-LMOF) displayed good performance as an electrode material for supercapacitors.

Ordered porous Mn3O4@N-doped carbon/graphene hybrids derived from metal–organic frameworks for supercapacitor electrodes

An ordered porous Mn3O4@N-doped carbon/graphene (MCG) composite has been synthesized through a facile carbonization of Mn-based metal–organic frameworks (Mn-MOFs) using the poly(styrene-co-AA) spheres as the template. Because of the periodic arrangement of metal nodes and organic ligands in the Mn-MOFs, the Mn3O4 nanoparticles with an average diameter of 7 nm are uniformly distributed and the carbon is formed in situ in the MCG composite. The MCG exhibits a specific surface area of 326 m2 g−1 with a total pore volume of 1.02 cm3 g−1, which is much higher than that of the Mn3O4-based composites reported to date. In addition, the MCG displays excellent electrochemical performances in an aqueous 1 M Na2SO4 electrolyte with a maximum specific capacitance of 456 F g−1 at 1 A g−1 and 246 F g−1 at 20 A g−1. The MCG also owns a good cycling stability with 98.1 % of the initial capacitance remaining after 2000 cycles at 5 A g−1.

To enhance the capacity of Li-rich layered oxides by surface modification with metal–organic frameworks (MOFs) as cathodes for advanced lithium-ion batteries

A Li-rich layered oxide, modified with Mn-based metal–organic frameworks (MOFs), shows a large discharge capacity, and good thermal stability as a cathode for lithium ion batteries.

Facile synthesis of MOF-derived Mn2O3 hollow microspheres as anode materials for lithium-ion batteries

In this article, we report a facile and scalable route for the fabrication of Mn2O3 hollow microspheres by direct pyrolysis of Mn-based metal–organic frameworks at 450 °C with a heating rate of 10 °C min−1 in air.

Carbon nanotubes@metal–organic frameworks as Mn-based symmetrical supercapacitor electrodes for enhanced charge storage

A hybrid material of carbon nanotubes (CNTs) and Mn-based metal organic frameworks (Mn-MOF) was synthesized and used as a Mn-based supercapacitor electrode material.

A transformative route to nanoporous manganese oxides of controlled oxidation states with identical textural properties

Controlled thermal conversion of Mn-based metal–organic frameworks yielded a series of nanoporous manganese oxides with continuously tuned oxidation states.

Nano- and microcrystals of a Mn-based metal–oligomer framework showing size-dependent magnetic resonance behaviors

A robust 3D Mn-based metal-organic framework containing metallosalen hexamers is synthesized and its nano- and microcrystals are fabricated by using surfactant-mediated hydrothermal and solvent precipitation methods; the particles exhibit an inverse size-dependent effect of magnetic resonance relaxivity behaviors.

Magneto-structural correlations of a three-dimensional Mn based metal–organic framework

A 3D metal-organic framework, [Na{Mn(3)(Hbtc)(2)(btc)}.5H(2)O](n) () (H(3)btc = 1,3,5-benzene tricarboxylic acid), was synthesized under hydrothermal conditions. The structure of was established by single crystal X-ray diffraction analysis; crystallizes in the monoclinic space group P2/c, a = 9.753(3) A, b = 12.751(2) A, c = 14.174(4) A, beta = 109.41(1) degrees . The complex is isostructural to previously reported MIL-45 and consists of one dimensional wave like chains of carboxylate bridged hexa-coordinated Mn(ii) ions. Variable temperature magnetic susceptibility measurements revealed dominant antiferromagnetic exchange interactions and the intra-chain exchange constants J(1) = -2.4 cm(-1) and J(2) = -0.6 cm(-1) compare well with literature values for similar materials. Inter-chain interactions are expected to be very small in this compound and there is no indication of magnetic ordering phenomena in the temperature range from 300-2 K.