Selektive Umwandlung multifunktionaler Biomassesubstrate mit in ionischen Flüssigkeiten stabilisierten Nanopartikelkatalysatorsystemen

Due to the increasing demand for energy carriers and fossil resources, as well as the rising anthropogenic CO2 emissions society faces the challenge of identifying new sustainable resources. In this context, biomass represents an attractive alternative because of its sustainability and its abundance. The catalytic conversion of biomass gives access to various chemical intermediates and potential fuels. As biomass exhibit many functional groups, generally it is converted into so-called platform molecules, which can be transformed to valuable chemicals by de- and refunctionalisation. This transformation requires new catalyst design as well was new process strategies to enable an efficient and selective access to the desired products. This thesis describes a new range of products from fufuralacetone accessible via multifunctional catalytic systems. At first, the potential products from furfuralacetone were identified and a suitable catalytic system was evaluated. Especially, in ionic liquids (IL) stabilised transition metal nanoparticles showed very promising activity and selectivity. It was possible to synthesis four different hydrogenation products starting from furfuralacetone selectively by employing various IL-stabilised nanoparticles. Particularly ruthenium nanoparticles stabilised in 1- dodecyl-3-methylimidazolium bis(trifluoromethansulfonyl)imid Ru@[C12MIM][NTf2] exhibited high activity and selectivity in the conversion of furfuralacetone to the fully hydrogenated product 2-(4-tatrahydrofuryl)-butanol. Furthermore, recycling experiments of Ru@[C12MIM][NTf2] showed no loss of reactivity or selectivity over fife cycles. In comparison to classic homogeneous and heterogeneous rutheniums catalyst the nanoparticles systems were much more reactive and tolerant towards biomass substrates and were able to hydrogenate various bio-based molecules. Moreover, by immobilising the nanoparticles on a solid support it was possible to apply the catalyst in continuous hydrogenation of furfuralacetone in supercritcial CO2. Modification of the nanoparticle systems was possible by functionalisation of the ionic liquids with sulfonic groups. The introduction of an acidic group lead to multifunctional catalytic systems with a redoxactive and an acidic site. These catalytic systems were very active in the hydrogenation and dehydration of 4-(2-tetrahydrofuryl)-butanol to 2-butyltetrahydrofuran and the C8-OL products 1-octanol and 1,1-dioctylether. By varying the ionic liquid and the reaction conditions it was possible to tune the selectivity to the desired product with a high selectivity towards secondary alcohols. Only traces of the fully hydrogenated product octane were observed. The combination of the hydrogenation step with the following hydrogenation and dehydration in a two step-one pot reaction gave access to the valuable C8-OL products with a selectivity of 93%. No purification in between was necessary. Furthermore, by immobilising the nanoparticles on acidic functionalised support it was even possible to recycle the catalytic system without loss in activity and selectivity. To conclude, the results of this thesis demonstrate that sensible catalyst and process design enables the synthesis of various products starting from the platform molecule fufuralaceton. The application of multifunctional ruthenium nanoparticles systems give access to valuable intermediates and potential fuels, which were not accessible before or only with poor selectivity

Synthesis of 1‐Octanol and 1,1‐Dioctyl Ether from Biomass‐Derived Platform Chemicals

Die goldene Mitte: Ein katalytischer Reaktionsweg zur Synthese der linearen primären C₈-Alkohole 1-Octanol und Dioctylether aus Furfural und Aceton wurde auf Basis einer retrosynthetischen Analyse entwickelt. Dies eröffnet einen allgemeinen Zugang zu Alkoholen mittlerer Kettenlänge aus Kohlenhydrat-Rohstoffen

St. John's Daily Star, 1920-11-19

The St. John's Daily Star was published daily except Sunday between 17 April 1915 - 23 July 1921

Selective ethenolysis and oestrogenicity of compounds from cashew nut shell liquid

The ethenolysis of cardanol (2), a waste product from cashew kernel production, was carried out using a variety of metathesis catalysts. Surprisingly, the best activities and selectivities could be observed with ruthenium based 1st generation type catalysts converting cardanol (2) almost completely to the corresponding 1-octene (6) and 3-non-8-enylphenol (4), a potential detergent precursor. Detailed investigation of the reaction system showed that the high activity and selectivity were due to a combination of ethenolysis and internal self-metathesis of the unsaturated cardanol mixture, 2. Self-metathesis of cardanol (2) containing three double bonds led to the formation of 3-non-8-enylphenol (4) and 1,4-cyclohexadiene (7). The latter was crucial for a high selectivity and activity in the ethenolysis, not only of cardanol (2), but also of other substrates like methyl oleate (10) when using ruthenium based 1st generation catalysts. The endocrine disrupting properties of 3-nonylphenol and related compounds are compared

Combinatorial characterisation of mixed conducting perovskites

One of the most common types of structure which displays Mixed Electronic Ionic Conductivity is the ABO3 perovskite. The perovskite structure defines a very large range of possible oxide compositions and thus, for screening as potential SOFC cathodes, new methods must be used to obtain a complete picture of these MIEC materials. Combinatorial methods offer a route to identify the major trends in functional properties prior to full scale experiment. The system La1 ? xSrxCo1 ? y ? zMnyFezO3 + ? (LSCMF) has been synthesised by combinatorial methods using a robot ink-dip printer. A systematic set of experiments was performed to characterise the trends in crystal structure, and non-stoichiometry with composition. It is the first time that this LSCMF pseudo-ternary has been measured with a 10% B-site substitution of cobalt, manganese and iro