Date of Award
Fall 9-5-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Daniel Killelea
Abstract
Metal-catalyzed oxidation reactions are a major application of heterogeneous catalysis and are a widely applied synthetic route for the production of chemicals and reagents essential to modern society. However, as the intricacies of heterogeneous surface catalysis are slowly being unraveled, minute details of the catalytic environment have been revealed to play outsized roles in the catalytic activity of the surface. The experiments herein further investigate the interplay between surface geometry and the formation oxygen-induced surface structures. Understanding how defects influence surface reactivity is a necessary step in gaining the ability to accurately model heterogeneous catalytic environments. Two different aspects of defects have been investigate in the paper herein. The first project was to understand how defect geometry influences the growth of oxygen induces surface reconstructions on c-Ag(111). We found that geometry may have an influence on the kind of surface reconstructions that nucleated, as well as inhibit the propagation of the surface reconstruction via changing the location of nucleation. However, the propagation of the reconstruction was inhibited to a much greater degree on the more narrow steps that were farther from the apex of the crystal. This leads to the second project, which was to understand how step width influences the growth of surface oxide on a bisected Rh(111)/(322) crystal. The crystal contains two separate surface facets: one with relatively large, flat terraces and the other with well defined, repeating, narrow steps. Oxidation and subsequent LEED analysis of this surface determined that oxide could grow on the highly stepped (322) half of the crystal under conditions where oxide would not be observed on a Rh(111) surface. These findings help strengthen the notion that defects have a direct influence on the growth of surface structures on metal model catalysts.
Recommended Citation
Gillum, Maxwell, "The Influence of Defects: Oxidation of Non-Planar Transition Metal Model Catalysts" (2025). Dissertations. 4237.
https://ecommons.luc.edu/luc_diss/4237
