Tomographic Reconstruction and Analysis of a Silver CO2 Reduction Cathode

Language
en
Document Type
Article
Issue Date
2020-12-30
First published
2020-05-19
Issue Year
2020
Authors
McLaughlin, David
Bierling, Markus
Moroni, Riko
Vogl, Christoph
Schmid, Günter
Thiele, Simon
Editor
Publisher
Wiley‐VCH Verlag GmbH & Co. KGaA
Abstract

Tomographic reconstruction has been well established as a valuable tool in the analysis of polymer electrolyte fuel cell (PEMFC) electrodes. While forays have been made into applying it to polymer electrolyte water electrolyzer (PEMWE) electrodes, CO2 electrolyzer electrodes are still new ground. Here a tomographic analysis of an electrochemical CO2 reduction gas diffusion electrode by means of focused ion beam scanning electron microscope tomography is presented. The reconstruction shows a porosity of 68%. While most of the porosity is on the nanoscale, a broad tail of micropores is observed in the distribution. The spatial distribution of the pores is nonuniform. The large pores are concentrated in the center of the layer in the through‐plane direction. From the reconstruction, an effective diffusivity factor of 0.5 for the catalyst layer is calculated. The Knudsen number of 0.19 obtained from the later shows that the diffusion is mostly in the bulk regime. Flooding of the catalyst layer is likely to decrease the effective diffusivity factor substantially.

Journal Title
Advanced Energy Materials
Volume
10
Issue
19
Citation
Advanced Energy Materials 10.19 (2020). <https://onlinelibrary.wiley.com/doi/10.1002/aenm.202000488>
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