Roenigk, Samantha
(2025)
Title Page
Controlling the Chemistry of Hydrogen at Platinum-Electrolyte Interfaces for Applications in Electrochemical Catalysis.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
The hydrogen evolution reaction (HER) is a critical process in electrochemical systems, serving as a method for the generation of dihydrogen (H₂) from water and offering a promising alternative to conventional steam methane reforming for hydrogen production. Platinum (Pt) is widely recognized as the most effective catalyst for the HER, which involves the combination of protons with electrons at the electrode-electrolyte interface. Consequently, extensive research has been devoted to the development of alternative catalysts for the HER, with Pt often serving as the benchmark standard in comparative studies. Benchmarking efforts are typically conducted under a range of conditions, employing either platinum nanoparticles (Pt NPs) or platinum supported on carbon (Pt/C) as reference materials. We have elucidated the degradation mechanisms of Pt NPs for the HER in impure electrolytes, an area that has received comparatively less attention in the context of catalyst stability and performance.
We have taken further advantage of the ability to manipulate the chemistry of hydrogen with Pt electrodes to explore the impact of temperature with applied potential on the electrocatalytic hydrogenation of CO2. Electrocatalysis research has been predominantly conducted near ambient temperatures in aqueous environments or through use of electrochemical devices with ceramic electrolytes that operate at greatly elevated temperatures (exceeding 500 °C). We chose CO₂ reduction as our model reaction due to its prominence and extensive study in both electrochemical and thermal catalysis research. The reaction is particularly intriguing because, while CO₂ reduction proceeds efficiently under thermochemical conditions at moderately elevated temperatures (200-400 °C) with H₂ and CO₂, it remains challenging to efficiently hydrogenate CO2 electrochemically at ambient temperatures. This begs questions about the extent to which thermal activation can be used in tandem with applied potential to accelerate the reaction.
We have developed an electrochemical reactor that incorporates features to simplify data interpretation and facilitate direct comparisons between thermal and electrochemical CO2 hydrogenation. This reactor was first benchmarked for its ability to activate and transport hydrogen between an anode and cathode, followed by measurements of CO2 hydrogenation using a Pt/C anode and copper supported on carbon (Cu/C) as the CO2 hydrogenation catalyst at the cathode.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
7 January 2025 |
| Date Type: |
Publication |
| Defense Date: |
10 September 2024 |
| Approval Date: |
7 January 2025 |
| Submission Date: |
14 November 2024 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
69 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Chemical and Petroleum Engineering |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
CO2RR, Electrolyzer, thermocatalysis,electrocatalysis, Pt NP |
| Date Deposited: |
07 Jan 2025 21:11 |
| Last Modified: |
07 Jan 2025 21:11 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/47080 |
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