Date of Award

2022

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Chemical and Biomolecular Engineering

First Advisor

Raymond J. Gorte

Abstract

With the increasing demands for sustainable energy and growing concerns of global warming, the use of biomass as a replacement for conventional petroleum has received considerable attention. Phenolic and furanic compounds derived from biomass could potentially serve as platform molecules with valuable chemical structures. However, the technologies to upgrade and utilize such molecules are still under development. This thesis aims to study the capabilities of oxides doped with metal-atom catalysts and metal-oxide, inverse catalysts to transform biomass platform molecules into useful chemicals, such as fuel, surfactant, and lubricants. Firstly, NbOx on Pt was found to be extremely active, selective, and stable for the direct deoxygenation of m-cresol, a model compound for phenolics. The metal-oxide overlayer was found to be the active site for the reaction while Pt itself hydrogenated the aromatic ring. This well-defined inverse catalyst structure was prepared by strong metal-support interactions (SMSI). To provide the H2 economically for the deoxygenation process, different oxides doped with isolated Co atoms were investigated for the dehydrogenation of ethane to ethylene. Atomic layer deposition (ALD) was shown to be able to synthesize the single atom structure readily, which is the active site for dehydrogenation. Lastly, aldol condensation of furfural, a furanic model compound, was investigated over the solid-base catalyst, CaO, to increase the carbon chain length. It was found that the aldol condensation rates are high when small ketones were used as the reactants. When larger ketones were used, the Cannizaro reactions could override the aldol condensation and lower the selectivity of furfural to high carbon products. The contributions from these studies should help develop catalytic processes for biomass valorization.

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