Details
| Original language | English |
|---|---|
| Pages (from-to) | F502-F513 |
| Number of pages | 12 |
| Journal | Journal of the Electrochemical Society |
| Volume | 165 |
| Issue number | 7 |
| Publication status | Published - 16 May 2018 |
Abstract
This study provides a direct comparison of hydrogen crossover in PEM (Nafion 117) and alkaline water electrolysis (Zirfon) at a temperature of 60?C applying state-of-the-art separating unit materials. To this end, occurring crossover mechanisms are described first, before experimental data of the anodic hydrogen content are shown in dependence of current density, system pressure and process management strategy. The results suggest that permeation in PEM electrolyzers is mainly governed by diffusion due to a supersaturated concentration of dissolved hydrogen within the catalyst layer, showing a share of 98% of the total permeation flux at 1Acm-2 and atmospheric pressure. Permeation in alkaline electrolyzers also exhibits a significant influence of supersaturation, but the overall crossover is mainly influenced by mixing the electrolyte cycles, which makes up a share of 90% at 0.7Acm-2 and 1 bar. Generally it becomes evident that hydrogen permeation across the separating unit is more than one order of magnitude smaller in alkaline electrolysis, which is mainly a consequence of the significantly lower hydrogen solubility in concentrated KOH electrolyte. Finally, this study concludes with an assessment of the impact of separating unit thickness and provides mitigation strategies to reduce hydrogen crossover.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Surfaces, Coatings and Films
- Chemistry(all)
- Electrochemistry
- Materials Science(all)
- Materials Chemistry
Sustainable Development Goals
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In: Journal of the Electrochemical Society, Vol. 165, No. 7, 16.05.2018, p. F502-F513.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Hydrogen Crossover in PEM and Alkaline Water Electrolysis
T2 - Mechanisms, Direct Comparison and Mitigation Strategies
AU - Trinke, P.
AU - Haug, P.
AU - Brauns, J.
AU - Bensmann, B.
AU - Hanke-Rauschenbach, R.
AU - Turek, Thomas
N1 - Funding information: The authors gratefully acknowledge the financial support by the Federal Ministry of Education and Research of Germany in the frame-work of PowerMEE (project number 03SF0536B) and the DFG in the framework of the projects INST 189/182-1 FUGG and TU 89/18-1. The authors gratefully acknowledge the financial support by the FederalMinistry of Education and Research of Germany in the framework of PowerMEE (project number 03SF0536B) and the DFG in the framework of the projects INST 189/182-1 FUGG and TU 89/18-1.
PY - 2018/5/16
Y1 - 2018/5/16
N2 - This study provides a direct comparison of hydrogen crossover in PEM (Nafion 117) and alkaline water electrolysis (Zirfon) at a temperature of 60?C applying state-of-the-art separating unit materials. To this end, occurring crossover mechanisms are described first, before experimental data of the anodic hydrogen content are shown in dependence of current density, system pressure and process management strategy. The results suggest that permeation in PEM electrolyzers is mainly governed by diffusion due to a supersaturated concentration of dissolved hydrogen within the catalyst layer, showing a share of 98% of the total permeation flux at 1Acm-2 and atmospheric pressure. Permeation in alkaline electrolyzers also exhibits a significant influence of supersaturation, but the overall crossover is mainly influenced by mixing the electrolyte cycles, which makes up a share of 90% at 0.7Acm-2 and 1 bar. Generally it becomes evident that hydrogen permeation across the separating unit is more than one order of magnitude smaller in alkaline electrolysis, which is mainly a consequence of the significantly lower hydrogen solubility in concentrated KOH electrolyte. Finally, this study concludes with an assessment of the impact of separating unit thickness and provides mitigation strategies to reduce hydrogen crossover.
AB - This study provides a direct comparison of hydrogen crossover in PEM (Nafion 117) and alkaline water electrolysis (Zirfon) at a temperature of 60?C applying state-of-the-art separating unit materials. To this end, occurring crossover mechanisms are described first, before experimental data of the anodic hydrogen content are shown in dependence of current density, system pressure and process management strategy. The results suggest that permeation in PEM electrolyzers is mainly governed by diffusion due to a supersaturated concentration of dissolved hydrogen within the catalyst layer, showing a share of 98% of the total permeation flux at 1Acm-2 and atmospheric pressure. Permeation in alkaline electrolyzers also exhibits a significant influence of supersaturation, but the overall crossover is mainly influenced by mixing the electrolyte cycles, which makes up a share of 90% at 0.7Acm-2 and 1 bar. Generally it becomes evident that hydrogen permeation across the separating unit is more than one order of magnitude smaller in alkaline electrolysis, which is mainly a consequence of the significantly lower hydrogen solubility in concentrated KOH electrolyte. Finally, this study concludes with an assessment of the impact of separating unit thickness and provides mitigation strategies to reduce hydrogen crossover.
UR - http://www.scopus.com/inward/record.url?scp=85053776451&partnerID=8YFLogxK
U2 - 10.1149/2.0541807jes
DO - 10.1149/2.0541807jes
M3 - Article
AN - SCOPUS:85053776451
VL - 165
SP - F502-F513
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 7
ER -