Metal-Organic stability compared to MOFs. However, ZIFs

Metal-Organic Frameworks (MOFs) are an interesting class of materials with high crystallinity and porosity. They are used for several potential applications, like gas separation and catalysis. There is a wide variety of MOFs known in literature, this number can be further increased by post-synthetic modi?cation (PSM) by which the metal-ion and/or the organic linker of the framework can be modi?ed or exchanged creating new properties for the material. A special subclass are the Zeolitic Imidazolate Frameworks (ZIFs), which have a zeolite-like topology providing extra chemical and thermal stability compared to MOFs. However, ZIFs aren’t used much in catalysis due to their low activity for most reactions. The activity can be increased by modi?cation of the framework, for example by exchanging the zinc(II)-ions with another (catalytically more active) metal(II)-ion. In this thesis, post-synthetic modi?cation of ZIF-8 by metal-ion exchange was studied. First ZIF-8 was synthesised in DMF, methanol and aqueous ammonia to ?nd the most promising candidate for the post-synthetic modi?cation. After the synthesis of ZIF-8 metal-ion exchange with manganese and cobalt was performed. With AAS and SEM-EDX the manganese and cobalt rates, after the metal-ion exchange reaction, were determined . A wide range of manganese rates was obtained, higher rates were obtained when performing the exchange reaction for longer times or at elevated temperatures. The cobalt rates found in the products were negligible. However, TEM results concluded that the metal-ions are not incorporated in the framework after the reaction but nanoparticles, which contained manganese, were observed at the surface of the particles

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