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Showing 1 to 20 of 23 for “"Supported Catalyst"”.
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(ASYMMETRIC) PHOTOCATALYSIS UNDER HOMOGENEOUS AND HETEROGENEOUS CONDITIONS - OPTIMIZATION IN CONTINUO, NOVEL CATALYTIC REACTORS AND MATERIALS
Solid supported catalysts exhibit several advantages over the homogenous ones – to name only a few: ease of catalyst separation and low catalyst loadings under continuous operation. This work shows how careful fine-tuning of solid supported material, transmission-based considerations (photocatalyst …
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Gas-Phase Epoxidation of Ethylene and Propylene
Catalysts consisting of silver on α-Al₂O₃, α-SiC, and β-SiC supports were synthesized and tested for catalytic performance in the gas-phase direct oxidation of ethylene to ethylene oxide. For this study, which used no promoters, ethylene oxidation selectivity of SiC-supported catalysts ranged from …
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Carbon Coating for Improved Hydrothermal Stability of Silica Supports
… Since the new feedstock is in aqueous phase the catalyst supports used currently in the petroleum-based chemical industry, such as silica and alumina, will not work because they are not hydrothermally stable. Silica and alumina are used as catalyst supports because they are mechanically stable, …
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Evaluation of TiO2 as a Pt-Catalyst Support in a Direct Ethanol Fuel Cell
… of ethanol. Difficulties lie in finding a catalyst that can completely oxidize ethanol and resist poisoning by intermediate reaction species. Degradation of the catalyst layer over time is also an issue that needs to be addressed. In this work, niobium doped-titanium dioxide (Nb-TiO2) is …
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The synthesis, characterization and activation of some multinuclear catalyst precursors for olefin polymerization
… were used as supports for homogeneous irconocene catalysts. The zirconium moiety was attached to the surface of the dendrimer through the ally! functionality. This was dope via hydrozirconation of the pendant C=C of the ally! groups on the periphery of the dendrimers. A number of model compounds …
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Structure and Ozone Decomposition Reactivity of Supported Manganese Oxide Catalysts
Manganese oxide catalysts supported on Al₂O₃, ZrO₂, TiO₂ and SiO₂ supports were used to study the effect of support on ozone decomposition kinetics. X-ray diffraction (XRD), in-situ laser Raman spectroscopy, temperature programmed oxygen desorption, surface area measurements, extended and near edge …
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A study of the copper oxide-aluminum oxide catalysts for the oxidation of carbon monoxide
The purpose of this study was to investigate the supported catalyst of the type CuO-Al₂O₃ which has been described by Lockwood and Frazer (13). This type of catalyst is unique in that it has a high activity at low temperatures, is suitable for use at high temperatures and has been reported to be …
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Nanosized iron crystallites for Fischer-Tropsch synthesis
… are cobalt and iron. In this work iron-based catalysts were studied. To ensure maximum metal utilisation and therefore a high weight specific catalytic activity, the metal crystallites should possess large specific surface areas and that is only achievable with small metal crystallites. …
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Supported aqueous phase catalysis
This work describes a novel family of catalysts denoted Supported Aqueous Phase Catalysts (S.A.P.C.). These catalysts consist of a water-soluble organometallic complex supported in a thin film of water residing on a high surface area hydrophilic solid; the reaction takes place at the water-organic …
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Structure Sensitivity of Alkane Hydrogenolysis on Ir/MgAl₂O₄ Catalysts
… systems, the catalytic performance of a metal supported catalyst would be affected by the size and shape of the metals, and this phenomena is called structure sensitivity. Generally, the structure sensitivity effect is considered being led by a combination of geometric property change and …
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Supported catalysts, from polymers to gold nanoparticles supports
… general goal of limiting their use is to find catalysts that can be reused and recycled thereby limiting the need for expensive metal precursors and metal waste. Strategies to recycle catalysts are multifold and range from the employment of soluble polymers as catalyst supports to the use of …
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Spectroscopic studies of Metal(II) complexes and application of the Ni(II) complexes to olefin oligomerisation catalysis
… nickel complexes prepared above was tested as a catalyst for the oligomerisation of 1-hexene. The experiments were carried out in batch at 40°C using toluene as solvent. Four different Lewis acid cocatalysts were tested and nickel : co-catalyst ratios of 1:1 and 1:10 were used. The effects of …
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Band engineering of metal oxide heterostructures for catalysis applications
Supported metal oxides are used as catalysts for a wide variety of industrially and environmentally important reactions such as the selective oxidation of hydrocarbons and alcohols and the selective catalytic reduction of nitrogen oxides. The support often plays an important role in the activity …
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Relationship between structure and electrochemical properties of direct methanol fuel cell anodes
… the high amount of expensive noble metals in the catalyst layers of direct methanol fuel cells (DMFC) is one of the most important prerequisites for a commercial application of the DMFC. The high catalyst loading of about 3-4 mg/cm² in both electrodes is today necessary because of poor electrode …
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DEVELOPMENT OF SUPPORTED COBALT CATALYST FOR FISCHER-TROPSCH SYNTHESIS
… chemicals. Understanding and developing FTS catalysts using mesoporous materials are of main interest in the present work. In the first step, the research focused on developing Co-based catalyst supported on multiwalled carbon nanotubes (MWCNTs). The functionalization of CNTs and its impact …
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Iridium oxide supported on graphitized carbon for use as reversal tolerant anodes in pem fuel cells
… is to include an oxygen evolution reaction (OER) catalyst which will decrease the overpotential for water electrolysis. The addition of the OER catalyst to generate a reversal tolerant anode (RTA) will therefore decrease the occurrence of the carbon corrosion at cell potentials below -1.2 V. Due …
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Comparing the performance of different catalyst packings for Fischer-Tropsch synthesis
… reactor technologies. However, conventional catalyst packings for fixed-bed reactors result in high pressure drop. Structured packings offer an attractive solution as their high porosity (ca. 70%-90%) when compared to that of conventional pellet- or particle packed beds (ca. 40%) results in …
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Development of Deactivation-Resistant Catalysts for Pd-Catalyzed C–N Cross-Coupling Reactions
… in a variety of fields, and Pd-based catalysts are among the most effective for these reactions. However, certain classes of compounds, including very bulky substrates as well as those containing coordinating functional groups, can be very difficult to couple. The choice of the …
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Deposition of Au/Pt on Co/SiO 2 for Fischer-Tropsch synthesis
Cobalt Fischer-Tropsch catalysts, which are used when the desired products are long chain, linear waxes and diesel [1], are promoted with noble metals [2].This is to primarily increase the reducibility of the cobalt oxide (Co3O4) phase present in the supported catalyst during preparation but also …
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