Analysis and Comparison of the Photodecomposition Reaction of Methanol on CeO2 Impregnated TiO2 Surfaces Versus Bare TiO2 Surfaces

<p>Titanium dioxide (TiO₂) has been well-studied primarily due to its unique photocatalytic activity. Different preparation techniques have been developed to increase its photocatalytic activity by various means, including simply increasing the surface area, changing the makeup of the framework, and modifying the surface with a dopant. This study focuses on the effect cerium oxide (CeO₂) has on the photocatalytic activity of TiO₂ by depositing CeO₂ on the TiO₂ surface. Methanol is used as a probe reactant for these experiments due to its wide use in heterogeneous catalysis research and the limited products that can form. Three-dimensional CeO₂ crystallites form on the 1 and 2 monolayer CeO₂-TiO₂ samples while crystals are not observed for the 0.5 or 0.25 monolayer samples. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) was used to characterize the surface chemistry occurring on these samples while a flow reactor was used to characterize the reaction products using a long path gas cell in a Fourier transform infrared spectrometer (FTIR). Except for the 1 monolayer sample, CeO₂ seems to increase the reaction and decomposition of organic compounds, especially chemisorbed methoxy groups, on the surface. The CeO₂ modified samples appear to adsorb molecular methanol less strongly than TiO₂. Upon UV irradiation, the CeO₂ modified samples desorb methoxy as methanol more so than TiO₂. All samples consistently produce carbon dioxide, water, formaldehyde, dimethyl ether, and methanol in the presence of ultraviolet light and oxygen.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2015

Author dc:creator

• Estes, Christopher A

Contributors dc:contributor

• Mark B. Mitchell
• Heather Abbott-Lyon
• Michael Van Dyke

• TiO2
• titanium dioxide
• CeO2
• cerium oxide
• photocatalysis
• methanol
• Chemistry
• Physical Chemistry

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/3

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1001