Synthesis and evaluation of CuO and Co-doped CuO nanofibers as electrocatalysts for nitrate reduction to ammonia
(2025) MVKM01 20251Department of Energy Sciences
- Abstract
- This master thesis investigates the synthesis, structural characterization and electrochemical performance of copper(II) oxide (CuO) and cobalt-doped CuO nanofibers as electrocatalysts for the electrochemical nitrate reduction reaction (NO3-RR). The overarching aim is to assess their potential for sustainable ammonia production under ambient conditions. A series of exploratory synthesis trials revealed significant sensitivity to lab-specific conditions as well as process details. Based on these findings, a final synthesis protocol involving electrospinning and thermal treatment was established, yielding nanofibrous CuO structures with and without cobalt doping. The materials were characterized using scanning electron microscopy (SEM) and... (More)
- This master thesis investigates the synthesis, structural characterization and electrochemical performance of copper(II) oxide (CuO) and cobalt-doped CuO nanofibers as electrocatalysts for the electrochemical nitrate reduction reaction (NO3-RR). The overarching aim is to assess their potential for sustainable ammonia production under ambient conditions. A series of exploratory synthesis trials revealed significant sensitivity to lab-specific conditions as well as process details. Based on these findings, a final synthesis protocol involving electrospinning and thermal treatment was established, yielding nanofibrous CuO structures with and without cobalt doping. The materials were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), confirming morphology, phase composition and cobalt integration.
Electrochemical experiments were performed in a two-compartment H-cell at neutral pH, employing both untreated and pre-reduced electrodes. Faradaic efficiency (FE) and electrochemically active surface area (ECSA) were used as primary performance metrics. The results indicate that pre-reduction has a pronounced effect on ECSA and initial electrode behavior, suggesting surface restructuring or phase transitions. However, its impact on faradaic efficiency varied depending on applied testing potential, showing positive effects only at the first (lowest) overpotential tested. Co-doped electrodes demonstrated improved faradaic efficiency in the lower overpotential range, possibly due to increased defect density and modified electronic structure.
Overall, this work emphasizes the dynamic nature of CuO-based catalysts during operation and the importance of pre-treatment history in performance evaluation. It also highlights the need for in situ or operando techniques to better capture transient surface states and guide catalyst optimization for selective NO3-RR to ammonia. (Less) - Popular Abstract
- Ammonia is an essential building block of modern agriculture, most notably as a key component in fertilizers. Traditionally, it is produced through the Haber–Bosch process, which is energy-intensive and heavily reliant on fossil fuels. At the same time, modern agriculture contributes to nitrate pollution in water systems, which poses environmental and health risks. What if we could tackle both problems with one solution?
This master thesis explores a promising technology that does just that: converting nitrate, a common pollutant, into ammonia using only electricity and specially designed materials known as electrocatalysts. Two versions of copper oxide (CuO) were studied: one pure and one with a small amount of cobalt added to modify... (More) - Ammonia is an essential building block of modern agriculture, most notably as a key component in fertilizers. Traditionally, it is produced through the Haber–Bosch process, which is energy-intensive and heavily reliant on fossil fuels. At the same time, modern agriculture contributes to nitrate pollution in water systems, which poses environmental and health risks. What if we could tackle both problems with one solution?
This master thesis explores a promising technology that does just that: converting nitrate, a common pollutant, into ammonia using only electricity and specially designed materials known as electrocatalysts. Two versions of copper oxide (CuO) were studied: one pure and one with a small amount of cobalt added to modify its properties. These materials were produced in the form of thin nanoscale fibers in the using a method known as electrospinning. After synthesis, the materials were examined under high-resolution microscopes and tested in a lab-scale setup to see how well they could convert nitrate into ammonia.
The experiments revealed that the performance of these catalysts depends not only on their composition but also on their preparation and treatment history. For instance, electrodes that were pre-treated by applying a specific voltage before testing behaved differently and sometimes more efficiently. Adding cobalt improved the performance at certain voltage. The study shows that even small changes in material composition or preparation can make a big difference in performance.
Ultimately, this research contributes to a growing field focused on sustainable chemical production. If scaled up, this approach could help reduce our dependence on fossil fuels, clean polluted water, and contribute to making fertilizer production more environmentally friendly. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9196126
- author
- Ehlde, Freja LU
- supervisor
- organization
- course
- MVKM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- ammonia synthesis, nitrate reduction, CuO, Co, doping, electrocatalysis, nanofibers, catalyst
- report number
- ISRN LUTMDN/TMPH-25/5655-SE
- ISSN
- 0282-1990
- language
- English
- id
- 9196126
- date added to LUP
- 2025-06-24 08:23:00
- date last changed
- 2025-06-24 08:23:00
@misc{9196126,
abstract = {{This master thesis investigates the synthesis, structural characterization and electrochemical performance of copper(II) oxide (CuO) and cobalt-doped CuO nanofibers as electrocatalysts for the electrochemical nitrate reduction reaction (NO3-RR). The overarching aim is to assess their potential for sustainable ammonia production under ambient conditions. A series of exploratory synthesis trials revealed significant sensitivity to lab-specific conditions as well as process details. Based on these findings, a final synthesis protocol involving electrospinning and thermal treatment was established, yielding nanofibrous CuO structures with and without cobalt doping. The materials were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), confirming morphology, phase composition and cobalt integration.
Electrochemical experiments were performed in a two-compartment H-cell at neutral pH, employing both untreated and pre-reduced electrodes. Faradaic efficiency (FE) and electrochemically active surface area (ECSA) were used as primary performance metrics. The results indicate that pre-reduction has a pronounced effect on ECSA and initial electrode behavior, suggesting surface restructuring or phase transitions. However, its impact on faradaic efficiency varied depending on applied testing potential, showing positive effects only at the first (lowest) overpotential tested. Co-doped electrodes demonstrated improved faradaic efficiency in the lower overpotential range, possibly due to increased defect density and modified electronic structure.
Overall, this work emphasizes the dynamic nature of CuO-based catalysts during operation and the importance of pre-treatment history in performance evaluation. It also highlights the need for in situ or operando techniques to better capture transient surface states and guide catalyst optimization for selective NO3-RR to ammonia.}},
author = {{Ehlde, Freja}},
issn = {{0282-1990}},
language = {{eng}},
note = {{Student Paper}},
title = {{Synthesis and evaluation of CuO and Co-doped CuO nanofibers as electrocatalysts for nitrate reduction to ammonia}},
year = {{2025}},
}