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Platinum Dissolution in Realistic Fuel Cell Catalyst Layers
Author(s) -
Ehelebe Konrad,
Knöppel Julius,
Bierling Markus,
Mayerhöfer Britta,
Böhm Thomas,
Kulyk Nadiia,
Thiele Simon,
Mayrhofer Karl J. J.,
Cherevko Serhiy
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202014711
Subject(s) - dissolution , mass transfer , catalysis , aqueous solution , platinum , chemistry , chemical engineering , inductively coupled plasma mass spectrometry , membrane , electrode , gas diffusion electrode , diffusion , deposition (geology) , diffusion layer , inorganic chemistry , mass spectrometry , electrochemistry , chromatography , thermodynamics , organic chemistry , paleontology , biochemistry , physics , sediment , biology , engineering
Pt dissolution has already been intensively studied in aqueous model systems and many mechanistic insights have been gained. Nevertheless, transfer of new knowledge to real‐world fuel cell systems is still a significant challenge. To close this gap, we present a novel in situ method combining a gas diffusion electrode (GDE) half‐cell with inductively coupled plasma mass spectrometry (ICP‐MS). With this setup, Pt dissolution in realistic catalyst layers and the transport of dissolved Pt species through Nafion membranes were evaluated directly. We observed that 1) specific Pt dissolution increased significantly with decreasing Pt loading, 2) in comparison to experiments on aqueous model systems with flow cells, the measured dissolution in GDE experiments was considerably lower, and 3) by adding a membrane onto the catalyst layer, Pt dissolution was reduced even further. All these phenomena are attributed to the varying mass transport conditions of dissolved Pt species, influencing re‐deposition and equilibrium potential.