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Nanostructured Ceria: Synthesis Characterization and Applications in Catalysis
Cerium oxide is a readily available commercial catalyst with extensive and far-ranging catalytic applications ranging from electrocatalysts, solid oxide fuel cells, to catalysts for organic reactions including dehydration of alcohols, hydrogenation of C=C bonds and oxidation of hydrocarbons. The unique activity of ceria catalysts stems from tunable physical properties such as oxygen vacancy defects (OVDs). However, there remains critical lack of information on the multiple features related to the catalytic activity. Therefore, this dissertation addresses the use of both traditional and non-traditional synthesis methodologies and thoroughly characterizes the chemical and structural features to establish fundamental understanding of the catalysts. The morphology of cerium oxide nanostructures has been associated with catalytic performance. By controlling the morphology, the exposure of targeted reactive facets can also be controlled, resulting in controlling the catalytic activity of the catalyst. This dissertation provides a detailed investigation into the structure-activity relationship for dismutation of H2O2 by morphologically selective ceria catalyst. Fenton-like reactions for H2O2 decomposition are among many ceria exhibits increased activity toward. The mechanism by which the decomposition occurs is surrounded by controversy due to differences in the catalyst nature and reaction conditions. This dissertation presents mechanistic determinations for the generation of reactive oxygen species resultant from the decomposition of H2O2. These studies combine experimental and computational insights. Direct production of methanol and complex oxygenates from carbon dioxide and hydrogen has been exalted as a valuable means to reuse carbon dioxide. Plasma reactions have been reported to convert carbon dioxide to carbon monoxide with high energy-efficiency, however plasma assisted catalytic conversion of carbon dioxide with hydrogen to methanol has shown low conversion and energy efficiency. As such, this dissertation further discusses the application of ceria nanoparticles in a modified dielectric barrier discharge (DBD) flow reactor toward the production of methanol from CO2 and H2 to elucidate the synergy between plasma and reducible catalysts with atomic oxygen and reactive oxygen species (ROS) moderating capability for atmospheric plasma-catalytic syntheses.
Chemistry|Physical chemistry|Inorganic chemistry
Fisher, Tamra J, "Nanostructured Ceria: Synthesis Characterization and Applications in Catalysis" (2020). ETD collection for University of Nebraska - Lincoln. AAI27956645.