Date of Award

Summer 8-10-2018

Level of Access Assigned by Author

Open-Access Thesis

Language

English

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

Brian G. Frederick

Second Committee Member

Thomas J. Schwartz

Third Committee Member

Rachel Austin

Additional Committee Members

Carl Tripp

Babara Cole

François Amar

Abstract

Hydrodeoxygenation of phenol to benzene using ruthenium supported titania catalysts strongly varies depending on the support crystal structure and preparation conditions. Here, we performed spectroscopic characterization of titania supports to identify the surface impurities common to commercial and synthesized titania samples using a variety of spectroscopic methods. Sulfate impurities were detected for the commercial anatase samples and a procedure for their elimination was proposed so that inactive catalysts gained reactivity. Surface hydroxyls of different TiO2 samples (anatase, rutile, and pyrogenic) were identified using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments performed on vigorously cleaned surfaces and a facet-specific assignment was proposed using DFT calculations performed by our collaborators. In addition, the electronic structure of TiO2 samples were studied using the reaction of vigorously cleaned TiO2 samples with H2/D2. Our results revealed that sulfate impurities of the commercial anatase samples change their electronic structure consistent with creation of deep electronic trap states within the band gap. Our results are used to derive structure-activity relationships for the Ru/titania catalyzed hydrodeoxygenation reactions of phenol.

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