Microscopic investigation of platinum deposition in PEMFC cross-sections using AFM and SEM
Autor: | Xiao-Zi Yuan, Stefan Helmly, Renate Hiesgen, Tobias Morawietz, K. Andreas Friedrich, Haijiang Wang |
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Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
Materials science
Cathodes Scanning electron microscope Nafion Analytical chemistry Proton exchange membrane fuel cell chemistry.chemical_element Crystallite growth law.invention Atomic force microscopy law Materials Chemistry Electrochemistry Deposition (phase transition) Proton exchange membrane fuel cell (PEMFCs) Deposition degradation Membrane degradation Platinum Membranes Renewable Energy Sustainability and the Environment Platinum depositions Polymer decomposition Conductive atomic force microscopy Condensed Matter Physics Proton exchange membrane fuel cells (PEMFC) Cathode Surfaces Coatings and Films Electronic Optical and Magnetic Materials Membrane chemistry Conductive AFM Postmortem analysis Pt deposition microscopy Crystallite Scanning electron microscopy |
Popis: | Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate platinum (Pt) deposition in the membrane of degraded proton exchange membrane fuel cells (PEMFCs). This study focuses on Pt distribution and microscopic aspects of accelerated membrane degradation. To facilitate post-mortem analysis, a 4-cell stack was specially designed with cells composed of two membranes. Considerable Pt deposition was observed in both membranes and at their interface. Significant crystallite growth in the form of a Pt band and membrane thinning was present in the membrane at the cathode side, which supports the hypothesis that Pt deposition accelerates polymer decomposition. Furthermore, a large continuous area of Pt crystals across the whole cathode membrane was detected. In addition, conductive AFM measurements revealed electronic connections across the membrane. These results indicate the formation of electronic short-circuits in the cell due to the accumulation of Pt particles, which has not been previously reported. Moreover, AFM proved to be more sensitive to detect Pt deposits and its effects than SEM. © 2013 The Electrochemical Society. All rights reserved. |
Databáze: | OpenAIRE |
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