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Showing 1 to 16 of 16 for “"Model Catalyst"”.
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Single-crystal metal oxides and supported metal nanoclusters as model catalyst sytems
… and Au and Cu nanoparticles that may be suitable catalysts for the catalytic oxidation of CO or hydrogenation of CO2. First, we examine the adsorption behavior of phenol on rutile TiO2(110) and ultrathin films of alumina prepared on a NiAl(110) substrate. Electron paramagnetic resonance studies …
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Compiling and optimizing spreadsheets for FPGA and multicore execution
… presents the RhoZeta spreadsheet compiler and Catalyst optimization system for programming multiprocessors and FPGAs. Any spreadsheet frontend may be extended to work with RhoZeta's multiple interpreters and behavioral abstraction mechanisms. RhoZeta synchronizes a variety of cell interpreters …
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Effects of Crystallite size and water partial pressure on the activity and selectivity of low temperature iron-based fischer-tropsch catalysts
… is a surface phenomenon, thus for optimum catalyst performance, maximum metal usage must be achieved. Therefore it is expected that the smaller the crystallite size of the metal, the more active the catalyst will be under test conditions. This work investigates the influence of iron …
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Preferential oxidation of carbon monoxide in hydrogen-rich gases over supported cobalt oxide catalysts
… of H₂ to H₂O. In this study, a Co₃O₄/γ-Al₂O₃ model catalyst was investigated as a cheaper alternative to the widely used noble metal-based ones. The CO oxidation reaction in the absence of hydrogen has been reported to be crystallite size-dependent when using Co₃O₄ as the catalyst. However, …
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Understanding the catalytic activity of oxides through their electronic structure and surface chemistry
… on transition metal oxides as alternative oxygen catalysts to costly and scarce noble metals. In order to develop descriptors to improve catalytic activity, thus reducing material cost for commercial technologies, this work studies fundamental processes that occur on model catalyst systems. …
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Model systems for the investigation of metal-support interactions in cobalt based Fischer-Tropsch
The catalyst used plays a pivotal role in the optimization of the Fischer Tropsch (FT) synthesis. Cobalt (Co)-based catalysts have been widely used in low temperature Fischer Tropsch synthesis for the production of longer chain olefins [1]. The interaction between the support and the active metal, …
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Copper-based nanostructured catalysts for efficient and selective CO2 electroreduction – synthesis, catalytic performance, and mechanistic analysis
… and wind). Among various materials, copper-based catalysts are most studied, given their unique capability to make hydrocarbons in considerable amounts and at reasonable overpotentials. In this thesis, in-depth understanding of the CO2 electroreduction process was firstly established by adjusting …
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The development of ceria-based catalysts for automotive after-treatment applications
… for the development of cost-effective industrial catalysts and is, therefore, the focal material for this work.<br/><br/>Modern internal combustion engine technology is being directed towards lean burn operation, involving higher air-fuel ratios in order to improve thermal efficiency. In turn, the …
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Investigation of the promotional effect of Cu and Ag on iron-based Fischer-Tropsch catalysts using ferrites as model catalysts
… The commercially used iron-based Fischer-Tropsch catalyst is supported on silica (Si), to improve the dispersion of the active metal and is promoted with small amounts of potassium to enhance the activity and selectivity of the catalyst and copper to enhance the reducibility of the iron oxide. …
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SYNTHESIS, CHARACTERIZATION, AND KINETIC EVALUATION OF PLANAR AND SUPPORTED HETEROGENEOUS CATALYSTS
… approach for biomass upgrading to fuels requires catalyst synthesis, characterization, and kinetic evaluation. The work was divided in three areas, 1-preparation and characterization of model catalysts containing metal oxide overcoats and metal nanoparticles synthesized by atomic layer deposition …
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Sintering of metal nanoparticles on model substrates
The sintering of precious metal catalysts is an important problem for the automotive and chemical process industry. As these precious metal catalysts sinter, the metal nanoparticles grow, which in return causes a loss in the overall surface area from loss of the number of available reaction sites. …
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The Chemical Synthesis of Model Catalysts Related to Enzymes
… in this thesis involve the chemical synthesis of model compounds designed to explore how trypsin and chymotrypsin may function. Since several lines of evidence indicate a catalytic role for histidine residues in these enzymes, it was proposed to prepare imidazole derivatives with carefully …
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Design and Mechanism Study of Electrocatalysts for Alkaline Hydrogen Evolution
… problem. Consequently, most of the alkaline HER catalysts, especially the highly cost-effective non-noble metal catalysts, are still inefficiently designed based on trial and error methods. This lack of knowledge surrounding the alkaline HER has not only affected the development of hydrogen-based …
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Adaptive control of electronic excitation utilizing ultrafast laser pulses
… the gas phase and involve one atomic and several model molecular systems. Absorption of femtosecond laser radiation by these systems induces an electronic excitation, and subsequently their ionization, photofragmentation or isomerization. The specific adjustment of the excitation laser field …
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Perovskites as New Support Materials for the Iron Based Fischer-Tropsch Synthesis
… sources such as coal, gas or biomass [1]. Iron catalysts and cobalt based systems are the preferred catalysts for the commercial Fischer-Tropsch synthesis (FTS) employed at PetroSA and Sasol in South Africa [2]. The use of iron catalysts is not only influenced by the low price of the active …
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Adding ammonia during Fischer-Tropsch Synthesis: Pathways to the formation of N-containing compounds
… NH₃ is added during FTS, using mostly iron based catalysts is investigated. In addition, the effect this has on the FTS reaction itself is evaluated. To achieve this goal, both theoretical and experimental techniques are used in this study. The CO adsorption and dissociation reactions are assumed …