Details
| Original language | English |
|---|---|
| Pages (from-to) | 62-66 |
| Number of pages | 5 |
| Journal | Journal of Power Sources |
| Volume | 393 |
| Early online date | 10 May 2018 |
| Publication status | Published - 31 Jul 2018 |
Abstract
The anode catalyst layer of a PEM water electrolyzer is reconstructed using a combination of FIB-SEM tomography and ionomer modeling. The pore space is infiltrated with silicone, enabling good discrimination between pores and IrRuOx catalyst material, while the ionomer cannot be imaged. The reconstructed volume of 29 μm × 24 μm x 7 μm contains catalyst particles with a median size of 0.5 μm and has a porosity of 55%. By modeling different ionomer contents inside the pore space, the impact on microstructural and transport parameters is investigated. At an ionomer content of 40-50% of the pore volume, all transport parameters are in a reasonable range, confirming experimental results from literature. At an ionomer content of 48% the catalyst layer has a porosity of 29%, a median pore size of 0.94 μm, a permeability of the pore space of 1.8mD and a mean ionomer film thickness of 0.4μm. The tortuosities of the ionomer and the pore space are calculated to 3.5 and 6.7 at the corresponding phase fractions of 26% and 29% respectively. The electrochemically active surface area estimated from the tomography (1.0m2g−1) is considerably lower than literature values, indicating a roughness below FIB-SEM resolution.
Keywords
- Catalyst layers, FIB-SEM tomography, Ionomer modeling, Microstructure, PEM water electrolyzers
ASJC Scopus subject areas
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Energy(all)
- Energy Engineering and Power Technology
- Chemistry(all)
- Physical and Theoretical Chemistry
- Engineering(all)
- Electrical and Electronic Engineering
Sustainable Development Goals
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In: Journal of Power Sources, Vol. 393, 31.07.2018, p. 62-66.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Three-dimensional microstructure analysis of a polymer electrolyte membrane water electrolyzer anode
AU - Hegge, Friedemann
AU - Moroni, Riko
AU - Trinke, Patrick
AU - Bensmann, Boris
AU - Hanke-Rauschenbach, Richard
AU - Thiele, Simon
AU - Vierrath, Severin
N1 - Funding information: We acknowledge funding by the German Federal Ministry of Education (BMBF) within the POWER-MEE project (Grant No. 03SF0536A ). The authors further thank Andrew Mondon and Brian Shanahan for their support.
PY - 2018/7/31
Y1 - 2018/7/31
N2 - The anode catalyst layer of a PEM water electrolyzer is reconstructed using a combination of FIB-SEM tomography and ionomer modeling. The pore space is infiltrated with silicone, enabling good discrimination between pores and IrRuOx catalyst material, while the ionomer cannot be imaged. The reconstructed volume of 29 μm × 24 μm x 7 μm contains catalyst particles with a median size of 0.5 μm and has a porosity of 55%. By modeling different ionomer contents inside the pore space, the impact on microstructural and transport parameters is investigated. At an ionomer content of 40-50% of the pore volume, all transport parameters are in a reasonable range, confirming experimental results from literature. At an ionomer content of 48% the catalyst layer has a porosity of 29%, a median pore size of 0.94 μm, a permeability of the pore space of 1.8mD and a mean ionomer film thickness of 0.4μm. The tortuosities of the ionomer and the pore space are calculated to 3.5 and 6.7 at the corresponding phase fractions of 26% and 29% respectively. The electrochemically active surface area estimated from the tomography (1.0m2g−1) is considerably lower than literature values, indicating a roughness below FIB-SEM resolution.
AB - The anode catalyst layer of a PEM water electrolyzer is reconstructed using a combination of FIB-SEM tomography and ionomer modeling. The pore space is infiltrated with silicone, enabling good discrimination between pores and IrRuOx catalyst material, while the ionomer cannot be imaged. The reconstructed volume of 29 μm × 24 μm x 7 μm contains catalyst particles with a median size of 0.5 μm and has a porosity of 55%. By modeling different ionomer contents inside the pore space, the impact on microstructural and transport parameters is investigated. At an ionomer content of 40-50% of the pore volume, all transport parameters are in a reasonable range, confirming experimental results from literature. At an ionomer content of 48% the catalyst layer has a porosity of 29%, a median pore size of 0.94 μm, a permeability of the pore space of 1.8mD and a mean ionomer film thickness of 0.4μm. The tortuosities of the ionomer and the pore space are calculated to 3.5 and 6.7 at the corresponding phase fractions of 26% and 29% respectively. The electrochemically active surface area estimated from the tomography (1.0m2g−1) is considerably lower than literature values, indicating a roughness below FIB-SEM resolution.
KW - Catalyst layers
KW - FIB-SEM tomography
KW - Ionomer modeling
KW - Microstructure
KW - PEM water electrolyzers
UR - http://www.scopus.com/inward/record.url?scp=85046835986&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2018.04.089
DO - 10.1016/j.jpowsour.2018.04.089
M3 - Article
AN - SCOPUS:85046835986
VL - 393
SP - 62
EP - 66
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
ER -