Shengchang Xiang

Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions

Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide. Here we show that a metal-organic frameworks (UTSA-16) displays high uptake (160 cm(3) cm(-3)) of CO(2) at ambient conditions, making it a potentially useful adsorbent material for post-combustion carbon dioxide capture and biogas stream purification. This has been further confirmed by simulated breakthrough experiments. The high storage capacities and selectivities of UTSA-16 for carbon dioxide capture are attributed to the optimal pore cages and the strong binding sites to carbon dioxide, which have been demonstrated by neutron diffraction studies.

Perspective of microporous metal–organic frameworks for CO2 capture and separation

It is emergent to reduce carbon dioxide emissions from fossil fuel combustion and thereby limit climate destabilization. In order to achieve the industrial scenario of CCS, there is a need for the discovery of better solid CO2 adsorbents that realize great improvement of selective capacity and stability to moisture as well as significant reductions in energy requirements and costs. In this review, we provide an overview of the current status of the emerging microporous metal–organic frameworks (MOFs) for the storage and separation of carbon dioxide. We summarize the main factors for CO2 capture performance of MOF materials under different working conditions, in comparison with those for zeolite materials. At the same time, we analyze the relationship among porous structures, pore/window sizes, capacity, selectivity and enthalpy of porous MOFs for CCS, which will give us clues for the design and synthesis of MOF materials as CO2 adsorbents.

Exceptionally high acetylene uptake in a microporous metal-organic framework with open metal sites

Six prototype microporous metal-organic frameworks (MOFs) HKUST-1, MOF-505, MOF-508, MIL-53, MOF-5, and ZIF-8 with variable structures and porosities were examined for their acetylene storage, highlighting HKUST-1 as the highest acetylene storage material ever reported with an uptake of 201 cm(3)/g at 295 K and 1 atm. To locate the acetylene binding sites within HKUST-1, neutron powder diffraction studies on acetylene loaded HKUST-1 were carried out and have conclusively established the significant contribution of open Cu(2+) sites for acetylene storage by their strong preferred interactions with acetylene molecules. The binding properties of acetylene gas at different sites were further investigated by first-principles calculations.

A robust near infrared luminescent ytterbium metal-organic framework for sensing of small molecules

The first near-infrared luminescent ytterbium metal-organic framework has been realized for the highly selective and sensitive sensing of small molecules.

A microporous luminescent metal–organic framework for highly selective and sensitive sensing of Cu2+ in aqueous solution

A luminescent metal-organic framework with small micropores for the enhanced recognition of Cu(2+) exhibits highly sensitive and selective sensing of Cu(2+) in aqueous solution.

Open Metal Sites within Isostructural Metal–Organic Frameworks for Differential Recognition of Acetylene and Extraordinarily High Acetylene Storage Capacity at Room Temperature

Chemical equcation Presented On the metal: Open metal sites within isostructural [M2(DHTP)] metal-organic frameworks (M = Co 2-, Mn2+, Mg2+, and Zn2+; DHTP = 2,5-dihydroxyterephthalate) exhibit differential molecular recognition with acetylene. The extremely strong interaction of Co2+with acetylene (see structure) makes [Co2(DHTP)] the highest volumetric acetylene storage material with a capacity of 230 cm3cm-3 at 295 K and 1 atm. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A microporous hydrogen-bonded organic framework for highly selective C2H2/C2H4 separation at ambient temperature.

The first microporous hydrogen-bonded organic framework with permanent porosity and exhibiting extraordinarily highly selective adsorptive separation of C(2)H(2) and C(2)H(4) at ambient temperature has been established.

A rod packing microporous metal–organic framework with open metal sites for selective guest sorption and sensing of nitrobenzene

A microporous MOF [Zn(4)(OH)(2)(1,2,4-BTC)(2)] (1,2,4-BTC = Benzene-1,2,4-tricarboxylate) with two immobilized open metal Zn(2+) sites was obtained by solvothermal reaction, which exhibits highly selective guest sorption and sensing of nitrobenzene.

Microporous metal-organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures

The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal–organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

A Homochiral Microporous Hydrogen-Bonded Organic Framework for Highly Enantioselective Separation of Secondary Alcohols

A homochiral microporous hydrogen-bonded organic framework (HOF-2) based on a BINOL derivative has been synthesized and structurally characterized to be a uninodal 6-connected {3(3)5(5)6(6)7} network. This new HOF exhibits not only a permanent porosity with the BET of 237.6 m(2) g(-1) but also, more importantly, a highly enantioselective separation of chiral secondary alcohols with ee value up to 92% for 1-phenylethanol.