Computational modeling of CO₂ electrocatalysis on surfaces and interfaces towards C₂ products
Abstract/Contents
- Abstract
- Atmospheric carbon dioxide (CO2) concentrations have continually increased to levels that far exceed pre-industrialization, largely due to our dependence on fossil fuels as a source of energy. This demands a renewable and clean source of energy for energy production; the sun is the largest resource at our disposal. The cost of electricity from renewable sources has seen a decline in recent years, leaving an open question of energy storage. To that end, we would like to take nature's design and use this renewable energy to produce solar fuels, similar to the natural process of photosynthesis. Ideally, we would like to reduce CO2 to valuable hydrocarbon products, especially to C2 compounds, which are more energy dense. Decades of research on the electrochemical CO2 reduction reaction (CO2RR) has showed that Cu is the only metal catalyst that can produce a variety of hydrocarbon products but at a low efficiency. Since these early findings, there have been many experimental and theoretical studies to both understand the catalysis on simple transition metal (TM) surfaces and design improved catalysts through a variety of techniques. This thesis is composed of 7 chapters. Chapter 1 is an introduction and details the current energy problem our planet is facing, a potential solution to this problem in the CO2RR, and prior research in CO2RR. Chapter 2 is the methodology and details the methods employed in this work. This includes density functional theory (DFT) to obtain energies of various adsorbed species during catalysis and analysis of this data using methods such as scaling relations and the computational hydrogen electrode. Chapter 3 involves calculations of C-C coupling barriers on various Cu facets at the electrochemical interface, including effects of electric fields, coverage effects, and strain effects. Chapter 4 uses some of these calculations as well as free energy diagrams to elucidate C-C coupling pathways on three facets of Cu: (100), (111), and (211). From our calculations, we advised our experimental collaborators to preferentially expose the (100) facet of Cu nanocubes, which showed an enhanced activity and selectivity towards C2 products. Chapter 5 includes some of these calculations as well as other barriers in the pathways to C2 compounds. These calculations are combined into a microkinetic model to predict reaction rates and compare well with experimental results. After gaining insight into C-C coupling on Cu, the best-known transition metal catalyst, chapter 6 then explores the metal-oxide
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Sandberg, Robert |
|---|---|
| Degree supervisor | Martinez, Todd J. (Todd Joseph), 1968- |
| Degree supervisor | Noerskov, Jens |
| Thesis advisor | Martinez, Todd J. (Todd Joseph), 1968- |
| Thesis advisor | Noerskov, Jens |
| Thesis advisor | Cargnello, Matteo |
| Degree committee member | Cargnello, Matteo |
| Associated with | Stanford University, Department of Chemistry. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Robert Barry Sandberg. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Robert Sandberg
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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