Aside from the desulfurisation, the denitrogenation of fuels is of great importance to minimze the environmental impact of transport emissions. The oxidative reaction pathway of organic nitrogen in the catalytic oxidative denitrogenation could be successfully elucidated. This is the first time such a pathway could be traced in detail in non-microbial systems.
View Article and Find Full Text PDFThe critical micelle concentrations (CMCs) of several imidazolium-based ionic liquids (ILs) in aqueous HO (50 wt % in HO) were determined by tensiometry, conductometry, and the rate of catalytic epoxidation of -cyclooctene. CMC values in aqueous HO were significantly lower compared to values in pure water. In both HO solution and water, the CMC of all ILs decreases with an increasing alkyl chain length and increases with a rising temperature.
View Article and Find Full Text PDFThe analysis of the thermal stability of supported ionic liquids (ILs) is of great interest for their application in catalysis. However, thermogravimetric (TG) measurements are very time-consuming, destructive, and cannot be conducted operando. Therefore, a new radio-frequency (RF)-based method is presented that analyzes the electrical properties of supported ILs in the microwave range and can detect a possible IL mass loss caused by evaporation or decomposition.
View Article and Find Full Text PDFPorous benzimidazole-based polymers (BILPs) have proven to be promising for carbon dioxide capture and storage. The polarity of their chemical structure in combination with an inherent porosity allows for adsorbing large amounts of carbon dioxide in combination with high selectivities over unpolar guest molecules such as methane and nitrogen. For this reason, among purely organic polymers, BILPs contain some of the most effective networks to date.
View Article and Find Full Text PDFIn order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H₂S.
View Article and Find Full Text PDFMethane originating from biogas or natural gas is an attractive and environmentally friendly alternative to gasoline. Adsorption is seen as promising storage technology, but the heat released limits fast filling of these systems. Here a lab scale adsorptive methane storage tank, capable to study the temperature increase during fast filling, was realized.
View Article and Find Full Text PDFThe vapour pressure and the thermal stability of liquids are important material properties. For high boiling organic and ionic liquids (ILs), the determination of these properties is laborious and it is not easy to discriminate between evaporation and thermal decomposition. In this work, a simple but accurate method is presented to determine the parameters of decomposition and evaporation by thermogravimetrical analysis (TGA).
View Article and Find Full Text PDFThe thermal stability of an ionic liquid (IL) is an important parameter and limits the maximum operation temperature. However, the definition of stability and of the maximum operation temperature, respectively, is still an open question. Typically, non-isothermal thermogravimetrical analysis (TGA) is used to determine the stability, which is then mostly defined by the onset temperature, i.
View Article and Find Full Text PDFThe desulfurization of fuel compounds in the presence of ionic liquids is reported. For this purpose, the desulfurization efficiency of a variety of imidazolium phosphate ionic liquids has been tested. Dibenzothiophene/dodecane and butylmercaptan/decane mixtures were used as model systems.
View Article and Find Full Text PDFThe gas-phase loading of [Zn(4)O(btb)(2)](8) (MOF-177; H(3)btb=1,3,5-benzenetribenzoic acid) with the volatile platinum precursor [Me(3)PtCp'] (Cp'=methylcyclopentadienyl) was confirmed by solid state (13)C magic angle spinning (MAS)-NMR spectroscopy. Subsequent reduction of the inclusion compound [Me(3)PtCp'](4)@MOF-177 by hydrogen at 100 bar and 100 degrees C for 24 h was carried out and gave rise to the formation of platinum nanoparticles in a size regime of 2-5 nm embedded in the unchanged MOF-177 host lattice as confirmed by transmission electron microscopy (TEM) micrographs and powder X-ray diffraction (PXRD). The room-temperature hydrogen adsorption of Pt@MOF-177 has been followed in a gravimetric fashion (magnetic suspension balance) and shows almost 2.
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