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The Role of the Platinum Band for Membrane Degradation in PEMFC – An Investigation using an Artificial Platinum Band

Friedrich, K. Andreas and Helmly, Stefan and Hiesgen, Renate (2014) The Role of the Platinum Band for Membrane Degradation in PEMFC – An Investigation using an Artificial Platinum Band. Carisma 2014, 1.-3. Dez 2014, Kapstadt, Südafrika.

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Abstract

The impact of the Pt band on ionomer degradation is controversial. Many studies found increased degradation in the presence of Pt deposits. However, in a recent publication, it was reported that the Pt band suppressed ionomer degradation.3 In their theoretical work, Gummalla et al. explained this discrepancy by the distribution of Pt particles: at low particle density, radicals are free to attack the ionomer, at high density, they are scavenged.4 Experimental results based on membranes in which Pt was deposited chemically support this theory.5,6 However, in those membranes, Pt particles were dispersed homogeneously, not locally as a thin band. In order to examine the influence of the Pt band more accurately, it is necessary to prepare membranes containing Pt particles which are distributed similarly to the Pt band. In this work, we investigated the role of Pt concentration in the Pt band on membrane degradation. For this purpose, we conducted a degradation experiment with membrane electrode assemblies (MEAs) containing an artificial Pt band with different amount of Pt. The MEAs contained two Nafion® membranes between which Pt was deposited mechanically. In the degradation test, they were operated with H2/O2 for ca. 100 h at open circuit voltage. Degradation was investigated based on electrochemical characterization and fluoride emission. In addition, Pt particle distribution at the membrane cross sections was analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). 1. A. B. LaConti et al., in Handbook of Fuel Cells: Fundamentals, Technology and Applications, Vol. 3, 647–663, Chicester, England (2003). 2. J. Aragane, J. Appl. Electrochem., 26, 147–152 (1996). 3. N. Macauley et al., ECS Electrochem. Lett., 2, F33–F35 (2013). 4. M. Gummalla et al., J. Electrochem. Soc., 157, B1542–1548 (2010). 5. M. P. Rodgers et al., J. Electrochem. Soc., 160, F1123–F1128 (2013). 6. S. Helmly et al., ECS Trans., 58, 969–990 (2013).

Item URL in elib:https://elib.dlr.de/93685/
Document Type:Conference or Workshop Item (Speech)
Title:The Role of the Platinum Band for Membrane Degradation in PEMFC – An Investigation using an Artificial Platinum Band
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Friedrich, K. Andreasandreas.friedrich (at) dlr.deUNSPECIFIED
Helmly, Stefanstefan.helmly (at) dlr.deUNSPECIFIED
Hiesgen, Renaterenate.hiesgen (at) hs-esslingen.deUNSPECIFIED
Date:1 December 2014
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:Polymer fuel cells, degradation, platinum band
Event Title:Carisma 2014
Event Location:Kapstadt, Südafrika
Event Type:international Conference
Event Dates:1.-3. Dez 2014
Organizer:Western Cape University
HGF - Research field:Energy
HGF - Program:Efficient Energy Conversion and Use (old)
HGF - Program Themes:Fuel Cells (old)
DLR - Research area:Energy
DLR - Program:E EV - Energy process technology
DLR - Research theme (Project):E - Electrochemical Processes (old)
Location: Stuttgart
Institutes and Institutions:Institute of Engineering Thermodynamics > Electrochemical Energy Technology
Deposited By: Friedrich, Prof.Dr. Kaspar Andreas
Deposited On:17 Dec 2014 17:23
Last Modified:17 Dec 2014 17:23

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