Journal
JOURNAL OF POWER SOURCES
Volume 196, Issue 23, Pages 9884-9889Publisher
ELSEVIER
DOI: 10.1016/j.jpowsour.2011.08.030
Keywords
Electrochemical surface area (ECA); Proton exchange membrane fuel cells (PEMFCs); Potential cycling; Pt/C catalyst; Switching power converter
Funding
- Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan [21760723]
- Grants-in-Aid for Scientific Research [21760723] Funding Source: KAKEN
Ask authors/readers for more resources
Proton exchange membrane fuel cells are operated using switching power converters that produce high-frequency ripple currents. These ripples cause high-frequency potential cycling of cells, which is believed to lead premature deterioration in the electrochemical surface area (ECA) of Pt/C catalysts. The qualitative relationship between ECA losses and the frequency of potential cycling was investigated in the range of 1 Hz to 1 kHz. For frequencies higher than 100 Hz, ECA losses were comparable with those at the potential hold condition. However, for lower frequencies. ECA decreased significantly with decreasing frequency. TEM observations showed that there was marked Pt particle growth for the 1-Hz cycling condition, whereas particle size distributions at 100 Hz and potential hold conditions were comparable. The currents associated with Pt oxidation and reduction during potential cycling were also investigated at various potentials and frequencies, and the charges associated with Pt loss (Delta Q) were determined by integrating the measured current. A correlation between the ECA trend and Delta Q was observed. The results obtained in this study are considered informative for electrical engineering research, because it relates to the design of switching power converters that do not negatively influence the Pt/C catalyst durability. (C) 2011 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available