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An impedance model for analysis of EIS of polymer electrolyte fuel cells under platinum oxidation and hydrogen peroxide formation in the cathode
journal contribution
posted on 2016-06-03, 10:53 authored by Samuel Cruz-Manzo, Cesar Perezmitre-Cruz, Paul S. Greenwood, Rui ChenIn this study, an impedance model based on electrochemical theory of platinum oxide formation has been developed and combined with the impedance model based on hydrogen peroxide formation during the oxygen reduction reaction (ORR) and reported in a previous study to characterise inductive loops in impedance spectra of polymer electrolyte fuel cells (PEFCs). To validate the theoretical treatment, the simulated frequency response predicted by the theoretical model is compared against electrochemical impedance spectroscopy (EIS) measurements carried out in an open-cathode 16 cm2 H2/air PEFC stack at three different current densities. The results show that neither model in isolation (hydrogen peroxide nor platinum oxide models) can accurately reproduce the inductive loops in the EIS measurements at low frequencies. By deriving a model considering kinetics of hydrogen peroxide and platinum oxide formation, it is possible to reproduce the inductive loops at low frequencies and to estimate the DC polarisation resistance related to the slope of the polarisation curve as frequency reaches zero during EIS. This study demonstrates that different mechanisms that cause PEFC degradation and low performance could be manifested in EIS measurements simultaneously. The resulting model could support other electrochemical techniques to quantify the rates of hydrogen peroxide and platinum oxide formation during the ORR that limit the performance of PEFCs.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
Journal of Electroanalytical ChemistryVolume
771Pages
94 - 105Citation
CRUZ-MANZO, S. ... et al., 2016. An impedance model for analysis of EIS of polymer electrolyte fuel cells under platinum oxidation and hydrogen peroxide formation in the cathode. Journal of Electroanalytical Chemistry, 771, pp.94-105.Publisher
© ElsevierVersion
- AM (Accepted Manuscript)