51. Plasma-Assisted Catalysis of Ammonia Using Tungsten at Low Pressures: A Parametric Study
- Author
-
Laurent Marot, Carlos Romero Muniz, Roland Steiner, Kunal Soni, Ernst Meyer, and Rodrigo Antunes
- Subjects
010302 applied physics ,Low pressure plasma ,Range (particle radiation) ,Materials science ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,Plasma ,Tungsten ,021001 nanoscience & nanotechnology ,01 natural sciences ,7. Clean energy ,Catalysis ,Ammonia ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,0210 nano-technology ,Radiofrequency plasma ,Parametric statistics - Abstract
The production of ammonia (NH 3 ) with low-pressure, radiofrequency plasmas is studied in this paper in a wide range of experimental conditions using tungsten as a catalyst. The relative position of the tungsten foil in the pyrex tube was observed to dramatically impact ammonia formation. By positioning the catalyst in the middle of the tube, the concentration of NH 3 peaked at 120 W with ≈20 mol %, while it decreased by more than a factor of 2 at 300 W. When the foil was placed close to the end of the tube, the production of NH 3 was rather stable beyond 120 W. These results provide clear evidence of the surface's role in the local enhancement of the NH 3 formation rates. In the plasma volume, at some distance from the foil, the decomposition of NH 3 is the major occurring process and the decomposition rate increases with the power primarily due to a higher electron density. The optimum production of NH 3 was found to be at 45 mol % N 2 and 120 W, and the position of the maximum was observed to slightly decrease to
- Published
- 2021