Reversed ethane/ethylene adsorption in a metal–organic framework via introduction of oxygen

Separation of ethane from ethylene is a very important but challenging process in the petrochemical industry.Finding an alternative method would reduce the energy needed to make 170 million tons of ethylene manufactured worldwide each year.Adsorptive separation using C2H6-selective porous materials to directly produce high-purity C2H4 is more energy-efficient.We herein report the"reversed C2H6/C2H4 adsorption"in a metal–organic framework Cr-BTC via the introduction of oxygen on its open metal sites.The oxidized Cr-BTC(O2)can bind C2H6 over C2H4 through the active Cr-superoxo sites,which was elucidated by the gas sorption isotherms and density functional theory calculations.This material thus exhibits a good performance for the separation of 50/50 C2H6/C2H4 mixtures to produce 99.99%pure C2H4 in a single separation operation.

Sticked-Layer Strategy to a Flexible-Robust Hydrogen-Bonded Organic Framework for Efficient C_(2)H_(2)/CO_(2)Separation

Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···πinteractions.The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction.HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.

Microporous metal-organic framework materials for efficient capture and separation of greenhouse gases

The release of anthropogenic greenhouse gases into the atmosphere poses serious risks to the environment and human health,and is a global threat of growing concern.In order to ameliorate the greenhouse gas emission problems,the efficient capture and separation of these greenhouse gases are greatly meaningful.Metal-organic framework(MOF)materials,a relatively new kind of organic-inorganic hybrid porous materials with unique framework features,tunable pore environment and high surface areas,have been widely studied as regards their applicability to this implementation.And the well-defined structures of MOF materials greatly promote the understanding of structure-property relationships.In this review,we intend to provide a profound account of significant progress in the field of capture and separation of greenhouse gases using MOFs as adsorbents,including carbon dioxide,methane,nitrous oxide and fluorocompounds(such as perfluorocarbons,sulfur hexafluoride,hydrochlorocarbons,and hydrofluocarbons).The strategies used to realize the efficient capture and separation of greenhouse gases have been summarized,and the relationships between the frameworks,their capture and separation performances and mechanisms are discussed.Furthermore,the existing challenges and perspectives with regard to the development of MOF materials for the capture and separation of greenhouse gases and industrial practical application are outlined to further promote this very significant and active emerging topic.

Metal-organic framework coated titanium dioxide nanorod array p-n heterojunction photoanode for solar water-splitting

This paper presents a p-n heterojunction photoanode based on a p-type porphyrin metal-organic framework (MOF) thin film and an n-type rutile titanium dioxide nanorod array for photoelectrochemical water splitting. The TiO2@MOF core-shell n anorod array is formed by coati ng an 8 nm thick MOF layer on a vertically aligned TiO2 nanorod array scaffold via a layer-by-layer self-assembly method. This vertically aligned core-shell nanorod array enables a long optical path length but a short path length for extraction of photogenerated minority charge carriers (holes) from TiO2 to the electrolyte. A p-n junction is formed between TiO2 and MOF, which improves the extraction of photogenerated electr ons and holes out of the TiO2 nano rods. In additi on, the MOF coati ng sign ificantly improves the efficie ncy of charge in jecti on at the photoanode/electrolyte interface. Introduction of Co(lll) into the MOF layer further enhances the charge extraction in the photoanode and improves the charge injection efficiency. As a result, the photoelectrochemical cell with the TiO2@Co-MOF nanorod array photoanode exhibits a photocurrent density of 2.93 mA/cm^2 at 1.23 V (vs. RHE), which is ~ 2.7 times the photocurrent achieved with bare T1O2 nanorod array under irradiation of an unfiltered 300 W Xe lamp with an output power density of 100 mW/cm^2.

A microporous aluminum-based metal-organic framework for high methane,hydrogen,and carbon dioxide storage

We report a microporous aluminum-based metal-organic framework(MOF),BUT-22 for high methane(CH_(4)),hydrogen(H_(2)),and carbon dioxide(CO2)storage.At 296 K and 80 bar,BUT-22 exhibits a high gravimetric CH4 storage capacity of 530 cm^(3)(STP)/g(0.379 g/g).BUT-22 also has a high gravimetric H_(2)storage capacity of 12 wt.%at 100 bar and 77 K.In addition,the CO_(2)adsorption studies revealed that BUT-22 exhibits a high absolute gravimetric CO2 uptake of 1.7 g/g at 296 K and 40 bar.

A flexible metal-organic framework with double interpenetration for highly selective CO2 capture at room temperature

1a Cu (FMA )(4,4-Bpe ) 的一个灵活金属器官的框架 0.5(FMA=fumarate；4,4-Bpe=trans-bis-(4-pyridyl ) 乙烯) 那个展览客人控制分子的门洞吸附被报导了，在哪个灵活毛孔能被公司 2 分子而非 CH 4 和 N 2 在某个门洞压力下面扩大。公司2举起能严厉地在 0.60 atm 从 6.85 厘米3 g -1被改进到 33.7 厘米3 g -1在 1 atm 由于门洞效果，因此为公司2/CH4导致显著地提高的吸附选择( 32:1 ， v/v )并且公司2/N2( 48:1 ， v/v )在房间温度的分离。

Controllable broadband multicolour single-mode polarized laser in a dye-assembled homoepitaxial MOF microcrystal

Multicolour single-mode polarized microlasers with visible to near-infrared output have very important applications in photonic integration and multimodal biochemical sensing/imaging but are very difficult to realize.Here,we demonstrate a single crystal with multiple segments based on the host-guest metal-organic framework ZJU-68 hierarchically hybridized with different dye molecules generating controllable single-mode green,red,and nearinfrared lasing,with the lasing mode mechanism revealed by computational simulation.The segmented and oriented assembly of different dye molecules within the ZJU-68 microcrystal causes it to act as a shortened resonator,enabling us to achieve dynamically controllable multicolour single-mode lasing with a low three-colour-lasing threshold of ~1.72 mJ/cm^(2)(approximately seven times lower than that of state-of-the-art designed heterostructure alloys,as reported by Fan F et al.(Nat.Nanotechnol.10:796-803,2015)considering the single pulse energy density)and degree of polarization>99.9%.Furthermore,the resulting three-colour single-mode lasing possesses the largest wavelength coverage of ~186 nm(ranging from ~534 to ~720 nm)ever reported.These findings may open a new route to the exploitation of multicolour single-mode micro/nanolasers constructed by MOF engineering for photonic and biochemical applications.

A two-dimensional microporous metal–organic framework for highly selective adsorption of carbon dioxide and acetylene

Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？ ？ 4.8 ？） functionalized by amino groups.Gas sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.

An ultrastable and easily regenerated HOF for the selective storage and separation of light hydrocarbons

Recently,crystalline porous materials such as metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)have attracted much interest not only in chemistry but also in materials science due to their tunable structures and functional channels.They have some inherent disadvantages of being difficult to solution process and recovery,which might limit their wide usage.As a new kind of porous crystals,hydrogen-bonded organic frameworks(HOFs)

A dynamic MOF for efficient purification of propylene

Propylene is an important chemical feedstock for making chemical products such as polypropylene and acrylonitrile,whereas propane is well-known for heating and cooking.Propylene and propane are usually found as a mixture since they come from steam cracking of heavy hydrocarbons like naphtha.The two differ by just two hydrogen atoms and have the same alkyl part,i.e.