Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 35 for “"carbon supported"”.
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So<sub>2</sub> Adsorption On Carbon-Supported Pt Electrocatalyst
… was about 75 times smaller with only the carbon support. Amounts that exceed monolayer coverage on Pt correspond to a spillover on the carbon support. The spillover of SO<sub>2</sub> was examined by varying the Pt loading and particle size to distinguish desorption temperatures. X-ray …
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Carbon Supported Metal Carbide Catalysts for the Reduction of Carbon Dioxide
… to air or passivation gases. The petcoke-based carbon prepared had higher surface areas and pore volumes (~2000 m2/g and > 1 cm3/g) than other commercial carbons (1000-700 m2/g and ~0.5 cm3/g) which enhanced the catalytic performance towards CO2 reduction. Microwave-assisted synthesis reduced …
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Development of sustainable carbon-supported catalysts for their incorporation into electrochemical devices
… a cabo la reducción electroquímica de dióxido de carbono (CO2RR), reacción clave para convertir CO2 en productos de mayor valor añadido. Reducir la energía necesaria para impulsar estas reacciones implica disminuir sus sobrepotenciales mediante catalizadores adecuados y condiciones operativas …
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Synthesis and characterisation of carbon supported gold catalysts prepared by ion-exchange
Gold has been previously overlooked as a catalyst, mainly because the metal has been regarded as catalytically inert, and was tested as large aggregates, and not as nanocrystallites. Large crystallites of gold do not exhibit significant catalytic activity, and if they do, their activity is small …
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Novel Carbon-supported Transition Metal Phosphide Catalysts for Hydrodeoxygenation of Fast Pyrolysis Oil
… of this research was to explore inexpensive supported metal oxides/metal phosphide catalysts for the upgrading of pyrolysis oil into advanced drop-in hydrocarbon liquid fuels by HDO. The first stage of this thesis project investigates a series of molybdenum oxides/phosphide catalysts on …
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Oxygen reduction reaction on carbon supported dispersed platinum nanoparticles and extended platinum surfaces
… on ORR activity by the development of platinum supported carbon electrodes. The surface morphology was modified by varying the platinum loading, such that the surface was taken from isolated nanoparticles to an extended surface. The effects of the changes in surface morphology and particle size …
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Evaluation of TiO2 as a Pt-Catalyst Support in a Direct Ethanol Fuel Cell
… compared to the common catalyst support, carbon. It has also been seen in the literature that TiO2 is able to adsorb OH and assist in freeing Pt sites by further oxidizing COad to CO2 and thereby increasing the catalytic activity of catalysts toward ethanol oxidation. The TiO2 support is …
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Structural Characterization and Phase Behavior in Supported Metallic Nanoparticles
The reductive condensation of a carbon-supported molecular cluster precursor, PtRu5C(CO)16, into a bimetallic nanoparticle has been followed by using in-situ extended X-ray absorption fine structure spectroscopy, temperature programmed desorption, and scanning-transmission electron microscopy. The …
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Electrochemical and NMR Studies of Fuel Cell Catalysts and Carbon Monoxide Surface Diffusion
… was also carried out for CO adsorbed on small carbon supported Pt nanoparticles. For fully and partially covered samples, diffusion coefficients (DCO) show a particle size dependence. That is, for the CO adsorbed on small Pt nanoparticles, the diffusion is slower as compared to CO on large Pt …
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Development of a sustainable water treatment technology for oxyanions using palladium-based catalysts: catalyst design, reaction mechanisms, and life cycle assessment
… water contaminants is catalytic reduction using supported Pd-based catalysts and an electron donor. While the technology is promising, several challenges need to be addressed before it is adapted by water treatment utilities. The overall goal of my thesis is to contribute to the development of …
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Metallic and bimetallic catalysts for electrochemical reduction of problematic aqueous anions
… also found to exhibit reduction at -300 mV and carbon-supported Pd/In, and the Pd/In/Au electrode were both found to catalyze nitrate reduction at an onset of approximately -200 mV vs. Ag/AgCl in a perchloric acid solution of pH 1. The high onset potentials in these systems are greater than 0 V …
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Oxygen reduction electrocatalysis
… activity of laccase is well established on carbon electrodes, laccase does not typically adsorb to better defined noble metal surfaces in an orientation that allows for efficient electrocatalysis. In this work, anthracene-2-methanethiol (AMT) was employed to modify the surface of Au …
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Gold catalysts prepared by ion exchange for use in ethylene glycol oxidation: An exploratory study
Heterogeneous catalysis using supported gold nanocrystallites has attracted increasing attention over the last two decades for its applicability to a wide range of reactions, offering activity under ambient conditions, as well as high selectivities towards particular products. This study focuses on …
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Anodic alcohol fuel cell reactions at platinum active sites on doped metal oxide supports
… via chemical reactions, which take place on the carbon supported platinum catalyst (Pt/C). As attractive as these devices may seem, their practicality is often limited by the functionality of the carbon support, which can be prone to corrosion. To limit the corrosion associated with a …
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Enhanced structural characterisation of supported catalysts
… characterisation of the size and shape of carbon supported nanoparticle catalysts. Both monometallic (Pt or Au) and bimetallic (PtPd) catalysts were studied. In the first results chapter the strengths and weaknesses of various structural characterisation methods, TEM, XRD and EXAFS were …
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Characterization of Anodic Fuel Cell Catalysts Utilizing Various Surface Sensitive Techniques
… optimized. The optimum palladium coverage for unsupported platinum black was theta = 0.79, whereas for carbon-supported platinum black it was theta = 1.39. The catalyst was also inspected via EC-IRAS, which indicated the presence of palladium on the surface and smaller particle sizes. It also …
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Electrocatalysts for the reduction of dioxygen and carbon dioxide
… Building on the prior ORR success of a carbon-supported binuclear copper complex of 3,5-diamino-1,2,4-triazole, the first section of this thesis focuses on four copper complexes built from structurally similar ligands which were synthesized and examined for their effectiveness as ORR …
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Continuous production of supported and shaped metal nanocatalysts using conveyor transport system
… technique to produce continuously a family of supported and shaped metal nanocatalysts in a single-step process. With carbon monoxide (CO) as a major species to mediate the surface structures of metals, highly uniform cubic Pt/C with narrow size distribution could be synthesized in a continuous …
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Preparation and characterisation of inorganic nanostructured support materials for polymer electrolyte fuel cells
… and high costs associated with the current carbon supported platinum (Pt/C) catalysts. Carbon support corrosion and Pt dissolution/aggregation on the catalyst layer within the fuel cell have been confirmed as the major contributors to the degradation of the Pt/C (Shao, et al., 2007). …
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Rapid screening of PEM FC cathode catalysts
… The catalytic properties of the Pt based carbon-supported catalysts were related to their structure e.g. particle size and lattice parameter, which were obtained mainly using Xray diffraction (XRD). It was found that the results acquired sing parallel screening methods were similar to …
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