Dissertation
Electrochemical conversion of CO2: effect of high pressure and electrolyte
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Autumn 2024
DOI: 10.25820/etd.007782
Abstract
Returning CO2 to the chemical supply chain as a renewable C1 feedstock can allow the closing of the carbon loop in chemicals and fuels manufacturing. Electrochemical conversion of CO2 is a promising method to achieve this. To help facilitate the adaption of this method for commercial and industrial applications, this work will work to utilize specialized catalyst supports to increase reaction rates and decrease catalyst cost by increasing the electrochemically active surface area of our catalyst supports. We will also design methods for evaluating experimental and computational catalyst design and develop energy efficient electrolysis reactions by experimenting with anode-boosted electrolysis, first paired with hydrogen evolution, which is a well-studied electrochemical reaction, and then with CO2 reduction. Finally, we examine the effect of high-pressure CO2 reduction when paired with the anode-boosting reaction. In this thesis, we show how carbon-based catalyst supports can be specially treated to allow greater catalyst loading. We also present methods for procuring SERS active catalysts and electrocatalyst supports which can be used to investigate the fundamental mechanisms that govern CO¬¬2 electrolysis. Understanding these mechanisms can facilitate the computational and practical design of novel CO2 electrocatalysts. Another major aspect of CO2 electrolysis is the counter reaction, which is typically the oxygen evolution reaction (OER), which suffers from sluggish kinetics and generates a product of low value (oxygen). It also requires large energy inputs and uses rare materials like iridium to catalyze the reaction. A major contribution is our work to show how a zero-gap electrolyzer can be used for hydrogen production, which is a valuable zero-emission fuel. CO2 reduction and hydrogen evolution can both be paired with anode reactions like methanol dehydrogenation for anode-boosted electrolysis. The CO2 reduction can be improved by increasing the partial pressure, and thus reaction rate for conversion. Therefore, we developed a high-pressure CO2 electrolysis system for investigation the alternative anodic reactions paired with CO2 reduction in an apparatus that allows for high pressure conditions to be applied.
Details
- Title: Subtitle
- Electrochemical conversion of CO2: effect of high pressure and electrolyte
- Creators
- Jacob P. Fields
- Contributors
- Syed Mubeen (Advisor)Chris Coretsopoulos (Committee Member)Joe Gomes (Committee Member)Johna Leddy (Committee Member)David Rethwisch (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Chemical and Biochemical Engineering
- Date degree season
- Autumn 2024
- DOI
- 10.25820/etd.007782
- Publisher
- University of Iowa
- Number of pages
- xviii, 136 pages
- Copyright
- Copyright 2024 Jacob P. Fields
- Language
- English
- Date submitted
- 08/08/2024
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 130-136).
- Public Abstract (ETD)
Carbon dioxide in the atmosphere contributes to the greenhouse effect and climate change. It is a ubiquitous end-product of innumerable chemical processes like the ones that drive our daily lives. By using carbon dioxide as a feedstock for chemical synthesis, it can be effectively stored as those chemicals and would be sequestered from the atmosphere. Further, these can be paired with renewable energy sources to drive the reactions. Before these kinds of systems can become viable and can represent a substantial sink for atmospheric carbon, some challenges must be overcome. Our work aims to overcome these challenges to deliver an improved system that can lead to disruptive technologies for sustainable chemical production.
- Academic Unit
- Chemical and Biochemical Engineering
- Record Identifier
- 9984774868902771
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