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Showing 1 to 20 of 51 for “"Supported catalysts"”.
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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 explored. …
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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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Development of sustainable carbon-supported catalysts for their incorporation into electrochemical devices
Las energías renovables se han consolidado como alternativa a los combustibles fósiles para reducir las emisiones de gases de efecto invernadero y mitigar el cambio climático. Sin embargo, su carácter intermitente requiere vectores capaces de almacenar y transportar energía de forma eficiente. …
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Studies of tartaric acid modified nickel supported catalysts for enantioselective hydrogenation reactions
… the catalytic properties of tartaric acid‐nickel supported catalysts, obtained from hydrotalcite‐like compound precursors, in the enantioselective hydrogenation of methyl acetoacetate to methyl 3‐hydroxybutyrate. Variables of reaction during modification such as pH and tartaric acid concentration, …
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Structure Sensitivity in the Subnanometer Regime on Pt and Pd Supported Catalysts
Single-atom and cluster catalysts have been receiving significant interest due to not only their capability to approach the limit of atom efficiency but also to explore fundamentally unique properties. Supported Pt-group single atoms and clusters catalysts in the subnanometer size regime maximize …
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Conversion of methyl ethyl ketone (MEK) to valuable chemicals over multifunctional supported catalysts
… the direct conversion of MEK to butene over supported copper catalysts (Cu-Al₂O₃, Cu-zeolite Y sodium (Cu-ZYNa) and Cu-zeolite Y hydrogen (Cu-ZYH)) in a fixed bed reactor. In this reaction, MEK is hydrogenated to 2-butanol over metal sites, and further dehydrated on acid sites to produce …
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Spectroscopic Studies and Reaction Mechanisms of Small Molecule Oxidation over Metal Oxide-Supported Catalysts
Chemical warfare agents are a toxic class of compounds that are incredibly harmful to human health. Methods of detoxification and decontamination currently exist, however they all suffer from problems that involve logistical transport or involve technologies that directly address liquid threats …
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Stepped single crystals as improved model for supported catalysts: Ethylene, methanol and assorted molecules on platinum(511) and platinum(331)
… from ethylene or ethane has been reported for supported platinum catalysts. A model for the methane formation on (1 x 1)Pt(110), was proposed by Yagasaki. In this study, the mechanism of methane formation has been further investigated, and Yagasaki's model tested, by studying the decomposition …
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Inclusion of Molybdenum into microporous and mesoporous materials
Transition metal supported catalysts have important value in industry and their developments continue to attract interest in research. Considering the importance of metal and metal oxide supported catalysts, this study focused on the development of molybdenum and molybdenum oxide supported …
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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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The Effects of Temperature and Reactive Environments on Metal Particle Sintering and Redispersion
… diketones to control redispersion of platinum supported catalysts.
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Structure sensitivity of H2/D2 Isotopic Exchange on Pt/Al2O3 catalysts
Pt-supported catalysts are widely used industrially for hydrogenation reactions. However, the kinetics of hydrogen activation, a critical step for any hydrogenation reaction, is still not well understood on supported Pt surfaces. Recent studies had shown that activity and selectivity vary with Pt …
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Metal-support interactions on Fe-based Fischer-Tropsch catalysts
… these interactions alters catalytic behavior in supported catalysts. The first theory is ‘the contact affect’, which is generally associated with partially reducible supports such as TiO2 [Tauster et al., 1978]. It is believed that the intimate contact between the partially reduced surface of the …
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The development of novel hetrogeneous catalysts for the hydrogenation of prochiral imines
Catalysts have been studied for the enantioselective hydrogenation of prochiral imines. Work has centred on the support of homogeneous catalysts, with the intention of establishing a heterogeneous catalyst without loss of activity. Initially, established heterogeneous systems were investigated. As …
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Oxidation of Carbon Monoxide Over Ceria and Alumina Supported Palladium Catalysts
<p>Palladium catalysts on both Al2O3 and CeO2, supports were studied for efficacy in low temperature carbon monoxide oxidation. Calcination temperatures were varied between 500-900°C for alumina supported catalysts and shown to have no significant difference in activity. X-Ray Photoelectron …
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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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A Study on Catalytic Sites Contiguity in Cu-ZnO-Based Catalysts for CO2 Hydrogenation to Methanol
… the CSC of atomically-dispersed ZnO-Cu/SiO2 catalysts for improving MeOH formation. Using the atomic layer deposition (ALD), atomically dispersed ZnO (ADZn2+) sites were engineered on uncalcined and calcined Cu/SiO2 samples. Characterizations revealed that Cu+–Cu0 and ADZn2+–Cu0/+ sites …
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Preparation and Characterization of Palladium Catalysts
… critical need for improved combustion-oxidation catalysts to reduce emissions of toxic volatile organic compounds (VOCs) emitted from exhaust gas of gasoline combustion in automotive vehicles. Materials and systems currently available, such as the three way catalytic converter (TWC), have low …
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ΡΥΘΜΙΣΗ ΤΩΝ ΕΠΙΦΑΝΕΙΑΚΩΝ ΦΟΡΤΙΩΝ ΚΑΤΑΛΥΤΙΚΩΝ ΦΟΡΕΩΝ ΜΕ ΤΗ ΧΡΗΣΗ ΤΡΟΠΟΠΟΙΗΤΩΝ
… THEREFORE, IT CAN BE USED FOR THE PREPARATION OF SUPPORTED CATALYSTS WITH HIGH ACTIVE SURFACE.
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