Electrochemical two-electron water oxidation toward hydrogen peroxide evolution
Abstract/Contents
- Abstract
- Hydrogen peroxide (H2O2) is a green chemical oxidant widely used for disinfection, water treatment, chemical synthesis, and paper bleaching. Industrially, H2O2 is produced through the energy-intensive anthraquinone process and distributed to the point-of-use. To mitigate the transportation cost and safety concern and to leverage the renewable electricity, a new approach has emerged to produce H2O2 onsite by electrochemically reducing O2 on the cathode and/or oxidizing water on the anode. Between these two reactions, the water oxidation reaction (WOR) is more desirable as it only needs water as the reactant and doesn't need continuous gas purging. Several pioneering works have demonstrated the feasibility of water oxidation to evolve H2O2 by using electrocatalysts, but it remains unclear what factors affect the activity and selectivity of the electrocatalysts. In my thesis work, I have investigated three aspects to facilitate the water oxidation reaction to evolve H2O2. First, our theoretical collaborators have suggested that the Gibbs adsorption energy of OH* on a catalyst surface is a descriptor to describe the activity and selectivity of WOR. I have experimentally verified the validity of overpotential and faradaic efficiency for H2O2 evolution by testing four metal oxide catalysts, i.e., WO3, BiVO4, SnO2, and TiO2. This study shows that BiVO4 has better activity and selectivity for WOR to evolve H2O2 than the other three catalysts. Second, our theoretical collaborators further use the descriptor ΔGOH* to screen and identify that ZnO with (101 ̅0) as the dominated facet will be a better catalyst than BiVO4. I have experimentally synthesized two types of ZnO, and demonstrated that one achieves the peak faradic efficiency of 80%, which is the highest among other reported catalysts. Finally, I built a photoelectrochemical device that uses BiVO4 as photoanode and electrocatalyst for water oxidation and CMK-3 carbon as electrocatalyst on the cathode for oxygen reduction. This device produces H2O2 on both electrodes under illumination and produces electricity simultaneously
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 | 2020; ©2020 |
| Publication date | 2020; 2020 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Shi, Xinjian |
|---|---|
| Degree supervisor | Zheng, Xiaolin, 1978- |
| Thesis advisor | Zheng, Xiaolin, 1978- |
| Thesis advisor | Cappelli, Mark A. (Mark Antony) |
| Thesis advisor | Prinz, F. B |
| Degree committee member | Cappelli, Mark A. (Mark Antony) |
| Degree committee member | Prinz, F. B |
| Associated with | Stanford University, Department of Mechanical Engineering. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Xinjian Shi |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering |
| Thesis | Thesis Ph.D. Stanford University 2020 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2020 by Xinjian Shi
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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