Electrochemical conversion of greenhouse gases and air pollutants: carbon dioxide, carbon monoxide, and nitrogen oxides
| Author(s) | Ko, Byung Hee | |
| Date Accessioned | 2023-02-24T13:19:30Z | |
| Date Available | 2023-02-24T13:19:30Z | |
| Publication Date | 2022 | |
| SWORD Update | 2022-09-21T16:07:43Z | |
| Abstract | Motivated by the need to mitigate greenhouse gas and air pollutant emissions and the decreasing price of renewable electricity, electrochemical conversion technologies have emerged as promising alternatives to existing technologies which typically rely on fossil fuels. Various molecules, including carbon dioxide (CO2), carbon monoxide (CO), and nitrogen oxides (NOx), can be electrochemically converted to value-added fuels and chemicals or harmless molecules. In this thesis, I present the remaining challenges, opportunities, and our efforts to advance the electrochemical technologies further to convert three sets of gases (i.e., CO2, CO, and NOx) via catalyst development, reactor engineering, reaction environment modification, and fundamental studies. ☐ I first examine the effect of NOx (i.e., nitric oxide, nitrogen dioxide, and nitrous oxide) in electrochemical CO2 reduction reactions on three model electrocatalysts (i.e., copper, silver, and tin). Because industrial CO2 point sources often contain gaseous impurities, understanding the effect of these impurities in electrochemical CO2 reduction reactions is crucial for practical application. ☐ Next, I develop a non-equilibrium synthesis method, in collaboration with the Liangbing Hu group at the University of Maryland, to synthesize a wide range of homogeneously mixed copper-based bimetallic catalysts regardless of the miscibility of the two metals and evaluate them in electrochemical CO reduction reaction towards multi-carbon (C2+) products formation. The non-equilibrium method gives access to novel catalysts that cannot be synthesized using conventional methods and provides an ideal platform to study the effect of secondary metals on the copper catalyst in electrochemical CO reduction reaction ☐ Then I develop the two-step electrochemical CO2 conversion process toward selective acetate and ethylene formation. CO2 is first converted to CO in the first electrolyzer, and CO is further converted to acetate and ethylene in the second electrolyzer. The flexibility to optimize two electrolyzers individually allows for a more effective C2+ products formation compared to direct CO2 electroreduction in one step. ☐ Lastly, I show an electrochemical route to convert NOx at high reaction rates (400 mA cm-2) under ambient conditions. Activity and selectivity of various transition metal catalysts are examined, and strategies to steer selectivity via reaction environment modification (i.e., NO coverages and electrolyte pH) are described. This work offers an alternative method to electrochemically abate NOx emissions using renewable electricity. | |
| Advisor | Jiao, Feng | |
| Degree | Ph.D. | |
| Department | University of Delaware, Department of Chemical and Biomolecular Engineering | |
| DOI | https://doi.org/10.58088/sxgk-xr88 | |
| Unique Identifier | 1371103138 | |
| URL | https://udspace.udel.edu/handle/19716/32355 | |
| Language | en | |
| Publisher | University of Delaware | |
| URI | https://login.udel.idm.oclc.org/login?url=https://www.proquest.com/dissertations-theses/electrochemical-conversion-greenhouse-gases-air/docview/2737178639/se-2?accountid=10457 | |
| Keywords | Air pollution | |
| Keywords | CO2 utilization | |
| Keywords | Electrocatalysis | |
| Keywords | Greenhouse gases | |
| Keywords | Sustainable energy | |
| Keywords | Carbon dioxide | |
| Title | Electrochemical conversion of greenhouse gases and air pollutants: carbon dioxide, carbon monoxide, and nitrogen oxides | |
| Type | Thesis |