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 14 of 14 for “"Metal-Support Interactions"”.
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Metal-support interactions on Fe-based Fischer-Tropsch catalysts
‘Metal support interactions’ is a term used to describe a phenomenon whereby the interaction between the active metal and the support material is strong enough to affect the catalytic activity and selectivity of the active phase. Primarily, there are two theories described in literature to explain …
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Inverse model systems to investigate metal-support interactions in Fischer-Tropsch catalysis
… thesis aims to gain insight into the effects of metal-support interaction in Co/SiO2 catalysts using an inverse model system by modifying Co3O4 nanocrystallites with silanes (i.e. tetraethoxysilane, trimethyl chlorosilane, triphenyl ethoxysilane). It is postulated that the formation of Co-O-Si …
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Model systems for the investigation of metal-support interactions in cobalt based Fischer-Tropsch
… chain olefins [1]. The interaction between the support and the active metal, Co, has been observed to affect the activity and selectivity of the FT synthesis [2]. In order to investigate metal support interactions independent of other support effects, the inverse method was used in the synthesis …
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Preferential oxidation of carbon monoxide in hydrogen-rich gases over supported cobalt oxide catalysts
… 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, studies looking at the effect of crystallite size during the CO-PROX reaction are …
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Spectroscopic Studies of Small Molecule Oxidation Mechanisms on Cu/TiO2 Aerogel Surfaces
… once a fundamental understanding of the interactions between material surfaces and adsorbed molecules is developed. In situ infrared spectroscopy and mass spectrometry methods were employed to probe interactions at the gas-surface interface of oxide-supported metal nanoparticle materials. …
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Alumina-modified cobalt catalysts for the Fischer-Tropsch synthesis
… studied for almost a century, the effects of the support material on activity, selectivity and stability of the catalyst remain obscure. This study aims to gain fundamental insights into the effect of metal-support interactions in cobalt alumina based Fischer-Tropsch catalysts. To accomplish this, …
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Structural and mechanistic identification of heterogeneous catalysts
… by issues including low weight loadings, strong metal-support interactions and heterogeneity in active component speciations. The following work details how these challenges may be addressed through a review of how a multimodal approach including scanning transmission electron microscopy, diffuse …
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SiC and B₄C as electrocatalyst support materials for low temperature fuel cells
Supported nano-catalyst technologies are key for increasing the catalyst utilisation and achieving economically feasible platinum metal loadings in hydrogen polymer electrolyte fuel cells (PEFCs). High surface area carbons are commonly utilised as support materials for platinum due to low cost, …
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Effect of Pt Particle Size and Electronic Properties on the Hydrogenation of Ethylene
… studies revealed that minor variations in the metal cluster size can affect both the geometric and electronic properties, which in turn affects the catalytic activity. Platinum (Pt) based catalysts on reducible oxides such as ceria (CeO2) have gained attention due to the support's ability to …
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Structure Sensitivity of Alkanes Hydrogenolysis and Alkynes Hydrogenation on Supported Ir Catalysts
… systems, the activity and selectivity of supported metal catalysts or extended metal surface catalysts would be affected by the metal surface structure, and this phenomenon is called structure sensitivity. Generally, structure sensitivity is led by the change of geometric and electronic …
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Synthesis, Characterization and Activity of Palladium Catalysts on the Dual Support of Cerium and Aluminum Oxides
… of Pd onto ceria due to strong PdO-CeOx interactions. This research implies that the sequence of impregnation and calcination temperature could alter catalytic properties and activity for methane combustion through PdO/PdOx -support interactions.</p>
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Synthesis and characterization of Pt/TiO2/C composite catalysts for fuel cells prepared using a glucose modifier
… are commonly dispersed on a conductive support and used as electrode materials in these devices because of their exceptional catalytic activity and electrochemical active surface area. The performance and stability of these electrodes strongly depend on the characteristics of the …
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Characterization of catalyst pellets using NMR and MRI: MRI, diffusion and relaxation measurements of liquid imbibed in alumina and titania extrudates
… coefficient of liquid contained within catalyst support pellets. Mass transport in catalyst pellets is often characterized through the tortuosity parameter, which impacts the catalyst effectiveness, though it is difficult to measure and simple relationships, such as tortuosity = 1/porosity, are …
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Supported Cobalt Oxide Catalysts for the Preferential Oxidation of Carbon Monoxide: An in situ Investigation
… in Co3O4 as a cheaper alternative to noble metals for the CO-PrOx reaction. However, the H2 (40 – 75%) in the CO-PrOx feed can also react with O2 (0.5 – 4%) to produce H2O, which consequently decreases the selectivity towards CO2 (based on the total O2 conversion). Aside from H2, the CO-PrOx …