Using Model Systems to Understand Catalysis on Thin Film Oxides, Supported Single Atoms, and Naturally Chiral Surfaces
Therrien, Andrew.
2017
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Abstract: Heterogeneous catalysts are used in approximately 90% of all
chemical products, including the petrochemical, pharmaceutical, and food industries. In
addition to chemical production, heterogeneous catalysts are becoming increasingly
important in energy storage and environmental chemistry. However, the rational design of
new and efficient catalyst has remained elusive, owed in large ... read morepart to the complexity of
heterogeneous catalysts and lack of fundamental understanding of various chemical processes
on surfaces. By taking a model study approach, the complexity of the catalytic surface is
reduced in order to allow for in-depth characterization and understanding of fundamental
reaction steps. Discoveries in surface science can inform the design of functional
catalysts, and thus establish a feedback loop. Several surface science techniques are
applied in this thesis, allowing for atomic-scale insight into surface structure,
electronic structure and charge state, key reaction step kinetics, and vibrational modes of
molecules. The model catalytic systems of interest in this thesis are thin film oxides,
supported single atoms, and enantioselective surface explosions. Oxide surfaces are
ubiquitous in nature, which make their study relevant to fields such as bulk oxidation,
corrosion, and catalysis. In addition to their own interesting surface chemistry, oxide
films can be used to model bulk oxides. Supported single atoms are a class of catalysts of
growing attention as the demand for precious metals continues to rise. By creating a
catalytic active site of a single atom the maximum metal efficiency can be achieved,
however, little is currently know about the nature of the active site and there still
exists no direct evidence that single atoms remain disperse under reaction conditions.
Therefore, much of the catalytic community has remained skeptical regarding the activity of
supported single atoms, and a model study approach is required to answer some of the
fundamental questions that remain. Finally, enantioselective catalysis is of great
importance to the pharmaceutical industry. However, enantiospecific reaction rates are
generally small. In order to further probe the capabilities of naturally chiral surfaces, a
curved crystal surface, which exposes many chiral facets, allows for the high-throughput
investigation of the surface structure on molecular adsorption and
reactivity.
Thesis (Ph.D.)--Tufts University, 2017.
Submitted to the Dept. of Chemistry.
Advisor: Charles Sykes.
Committee: Arthur Utz, Yu-Shan Lin, and Michelle Foster.
Keyword: Chemistry.read less - ID:
- df65vm115
- Component ID:
- tufts:24333
- To Cite:
- TARC Citation Guide EndNote