RESUMO
Novel ruthenium-based supported ionic liquid phase (SILP) catalysts for the water-gas shift (WGS) reaction are reported which, compared to classical low temperature shift systems, operate at much lower temperatures and even at ambient pressure.
RESUMO
The fragmentation pathways of allenylidene and carbene complexes have been studied using FAB mass spectrometry in comparison with thermal analyses (TGA, DrTG and DTA). Both the decomposition modes are investigated and the possible fragmentation pathways are suggested. The use of mass and thermal analyses (TGA and DTA) in the analyses of allenylidene and carbene complexes allowed the characterization of the fragmentation pathways in MS. The major pathway includes successive loss of carbon monoxide followed by fragmentation of the organic part of the allenylidene or carbene molecules. This is also confirmed by thermogravimetric analysis (TGA) where the first step involves the loss of carbon monoxide followed by the organic ligand. The nature of each step; exothermic or endothermic, is also studied using DTA technique. The kinetic parameters of the thermal decomposition are also studied using the Coates-Redfern method.
Assuntos
Alcenos/química , Carbono/química , Análise Diferencial Térmica/métodos , Espectrometria de Massas/métodos , Metano/análogos & derivados , Termogravimetria/métodos , Monóxido de Carbono/química , Gases , Temperatura Alta , Cinética , Ligantes , Metano/química , Modelos Químicos , Nitrogênio/química , Solventes/química , Temperatura , TermodinâmicaRESUMO
Supported Ionic Liquid Phase (SILP) catalysts have been prepared by effective immobilization of [Cu(TMEDA)(OH)]Cl in a nano-metric film of an ionic liquid on various oxidic support materials. The catalysts were tested for the oxidative homocoupling of 1-alkynes to the corresponding diynes in in a combined high throughput and conventional batch reaction approach. Among the screened support materials silica based materials performed best. The results indicate that for the specific reaction the thickness of the ionic liquids layer and therefore the mobility of the homogeneous copper complex within the ionic liquid layer as deduced from solid state nmr measurements have major impact on the catalytic performance. The optimized catalysts could be recycled up to four times without any loss of activity.