Electrocatalysis at the atomic scale: Complexities at the electrode-electrolyte interface
Restricted (Penn State Only)
- Author:
- Wong, Andrew
- Graduate Program:
- Chemical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 14, 2024
- Committee Members:
- Robert Rioux, Professor in Charge/Director of Graduate Studies
Robert Rioux, Major Field Member
Robert Rioux, Special Member
Ismaila Dabo, Outside Unit & Minor Member
Raymond Schaak, Outside Field Member
Michael Janik, Chair & Dissertation Advisor - Keywords:
- DFT
electrocatalysis
heterogeneous catalysis
computational chemistry
electrochemistry
surface science
interfaces
chemical engineering
cations
CO2 reduction
wastewater remediation - Abstract:
- The abundance of renewably sourced electricity has created new opportunities in the sustainable production of chemicals and fuels. Electrocatalysis plays a pivotal role in this transition, facilitating transformation between electrical and chemical energy under ambient conditions and the use of cleaner reagents. However, these systems are often limited by the electrocatalysts themselves, which are limited by excessive overpotentials requirements, poor selectivity, and/or instability of the catalyst. Design principles for electrocatalysts remain in their infancy due to the convolution between the interplay of catalytic kinetics and the complexities within the electrode-electrolyte interface or the electrochemical double layer (EDL). Therefore, it is crucial to deconvolute the complexities within the EDL and investigate how these different phenomena can be leveraged for the design of electrocatalysts. In this dissertation, Density Functional Theory (DFT) calculations were used to untangle the complexities of electrocatalysis by separating key complexities into the following three sections: 1. electrode-adsorbate interactions (Chapters 2 and 3), 2. influence of the EDL on electrokinetics (Chapters 3 and 4), and 3. the propensity of ions to specifically adsorb (Chapters 5 and 6). Lastly, these complexities are integrated together to study cation effects on CO2 electrochemical reduction on Au (Chapters 8 and 9). DFT was shown to be an insightful tool in elucidating complexities at the atomic scale, linking these phenomena to the experimental design of electrocatalysts. Recommendations for future research prioritizing models beyond DFT and phenomena not discussed in depth in this dissertation are denoted in the last chapter.