Metal-organic frameworks MOFs properties

The design and synthesis of metal-organic frameworks (MOFs) has yielded a large number of solids that possess useful gas and liquid adsorption properties. In particular, highly porous structures constructures constructed from discrete... 

Recently, an alternative strategy has been adopted to synthesize metal or semiconductor nanomaterials by exposing precursor metal-organic frameworks (MOFs) to an electron beam. Jacobs et al. (2011) demonstrated the formation for ZnO particles with narrow and tunable size distributions using different Zn-based MOFs. They showed that the composition, size, and morphology of the nanoparticles are determined by the chemistry and structure of the MOF, as well as the electron beam properties. 

Apart from zeolites and clays, other materials, such as metal-organic frameworks (MOFs), have also been explored as template to produce porous carbons. Recently, Liu et al. have synthesised porous carbon by heating the carbon precursor furfuryl alcohol within the pores of MOF-5. The resultant carbon exhibits high specific surface area up to 2872 m g and high pore volume of 2 cm g but possesses both micropores and mesopores. This porous carbon material shows good hydrogen uptake of 2.6 wt% at 760 Torr and —196 °C, as well as excellent electrochemical properties as an electrode material for an electrochemical double-layered capacitor. 

Metal-organic frameworks (MOFs) are three-dimensional extended structures in which metal ions or clusters are linked through organic molecules that have two or more sites through which links can be formed. Unlike coordination polymers, MOFs are exclusively crystalline the trademarks of MOFs are their extremely high surface areas, tunable pore size, and adjustable internal surface properties. Functional groups that link metals or metal clusters within MOFs are molecules or ions that have two or more Lewis basic sites (for example, carboxylates, triazolates, tetrazolates, ° and pyrazolates (Figure 9.36)). 

The dobdc ligand (Figure 9.36d) shows remarkable versatility for metal-organic frameworks. MOFs of the general formula M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn) have been prepared. The chemical and physical properties of M2(dobdc) MOFs are heavily influenced by the specific metal ion incorporated. Figure 9.40 shows a two- and three-dimensional perspective of the pores formed by Zn-MOF-74 (Zn2(dobdc)). ... 

This is not to say that all has been discovered about these materials. New solids are continually being synthesised, and the rapidly developing field of porous metal organic frameworks (MOFs) is a current example. The applica-bihty of microporous solids is continually being extended within the traditional fields of adsorption, catalysis and ion exchange. One exciting application explores their use as catalysts in the manufacture of fine chemicals. Other emerging areas of research concern their potential use in medicine or in devices that require speeial electronic or optical properties. 

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