Abstract
Electrochemical reaction kinetics at the electrodes of Solid Oxide Cells (SOCs) were investigated at 700 °C for two cells with different fuel electrode microstructures as well as on a third cell with a reduced active electrode area. Three fuel mixtures were investigated – hydrogen/steam and reformate fuels hydrogen/carbon-dioxide and hydrogen/methane/steam. It was found that the kinetics at the fuel electrode were exactly the same in both reformates. The hydrogen/steam fuel displayed slightly faster kinetics than the reformate fuels. Furthermore the gas conversion impedance in the hydrogen/steam fuel split into two processes with opposing temperature behavior in the reformate fuels. An 87.5 % reduction in active electrode area diminishes the gas conversion impedance in the hydrogen/steam fuel at high fuel flow rates. In both reformates, the second and third lowest frequency processes merged into a single process as the gas conversion was reduced. The SOC with finer electrode microstructure displayed improved kinetics.
| Original language | English |
|---|---|
| Journal | Journal of The Electrochemical Society |
| Volume | 163 |
| Issue number | 13 |
| Pages (from-to) | F1451-F1462 |
| Number of pages | 12 |
| ISSN | 0013-4651 |
| DOIs | |
| Publication status | Published - 2016 |
Bibliographical note
© The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.Keywords
- Continuously stirred tank reactor
- Electrochemical impedance spectroscopy
- Electrode potential
- Gas conversion
- Kinetics
- Plug flow
- Pseudo-gas conversion
- Reformate fuel
- Solid oxide fuel cell