Dissertation
A study of bimetallic palladium and copper electrocatalysts for the electrochemical oxidation of formate and reduction of CO2 into formate and ethylene
Washington State University
Doctor of Philosophy (PhD), Washington State University
2022
DOI:
https://doi.org/10.7273/000005085
Abstract
This study focuses on fuel cells using formate (HCOO-) and the electrochemical conversion of carbon dioxide (CO2) into HCOO- and ethylene. HCOO- has been considered as one of those promising alternative energy carriers, which can be fed into a direct HCOO- fuel cell (DFFC) to generate electricity via the HCOO- oxidation (FO) reaction (FOR). Moreover, HCOO- can be produced via the electrochemical reduction of CO2 (eCO2R). This makes possible the development of a sustainable, regenerative energy system combining an eCO2R unit and a DFFC to produce electricity with net zero CO2 emission. Furthermore, HCOO- can be fed into an electrochemical reforming reactor to produce hydrogen (H) via FOR. In addition, CO2 can also be reused to produce valuable C2 compounds such as ethanol, ethylene etc., which are conventionally produced via energy-intensive processes. Amongst catalysts, palladium (Pd) is one of the few metals that can be used for both, the FOR and the eCO2R into HCOO- (eCO2RF) at low overpotential. For the electrochemical reduction of CO2 into C2 compounds (eCO2RC2), multiple studies have focused on using copper (Cu) as the electrocatalyst. However, the low current density and high cost of Pd prohibit its application as an electrocatalyst at the industrial scale. In this research, we investigated two nano-catalysts aiming to improve the catalytic activity of Pd-based materials for the FOR and eCO2RF. This was achieved by modifying the electronic surface property of the catalysts via synthesizing bimetallic Pd-based nanoparticles (NPs). Carbon supported CuPd (CuPd/C), Iron@Iron Oxide (Fe@FeOx) supported Pd (Fe@FeOx/Pd) NPs were prepared via the adsorbate-induced surface segregation method and the successive salt reduction method, respectively. The eCO2RC2 were also investigated on the surface with different electronic properties: aluminum (Al), Cu, Cu (I) oxide (Cu2O), Cu (II) oxide (CuO), stainless steel 304, and titanium (Ti). Finally, since C2 compounds can also be used as fuel to generate H2, we have studied the oxidation of ethanol using the caustic aqueous phase electrochemical reforming process, which converts liquid oxygenated hydrocarbons at high-pressure to high purity H2. This process captures the produced CO2 within the electrolyte solution producing a near-zero CO2 emission.
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Details
- Title
- A study of bimetallic palladium and copper electrocatalysts for the electrochemical oxidation of formate and reduction of CO2 into formate and ethylene
- Creators
- Wei Jyun Wang
- Contributors
- Su Ha (Advisor)Louis Scudiero (Advisor)Di Wu (Committee Member)Steven R. Saunders (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 161
- Identifiers
- 99901019236501842
- Language
- English
- Resource Type
- Dissertation