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Advances in Energy Research Volume 2, Number 2, June 2014 , pages 073-84 DOI: https://doi.org/10.12989/eri.2014.2.2.073 |
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Influence of the cathode catalyst layer thickness on the behaviour of an air breathing PEM fuel cell |
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Paloma Ferreira-Aparicio and Antonio M. Chaparro
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| Abstract | ||
| Fuel cells of proton exchange membrane type (PEMFC) working with hydrogen in the anode and ambient air in the cathode („air breathing‟) have been prepared and characterized. The cells have been studied with variable thickness of the cathode catalyst layer (LCL), maintaining constant the platinum and ionomer loads. Polarization curves and electrochemical active area measurements have been carried out. The polarization curves are analyzed in terms of a model for a flooded passive air breathing cathode. The analysis shows that LCL affects to electrochemical kinetics and mass transport processes inside the electrode, as reflected by two parameters of the polarization curves: the Tafel slope and the internal resistance. The observed decrease in Tafel slope with decreasing LCL shows improvements in the oxygen reduction kinetics which we attribute to changes in the catalyst layer structure. A decrease in the internal resistance with LCL is attributed to lower protonic resistance of thinner catalyst layers, although the observed decrease is lower than expected probably because the electronic conduction starts to be hindered by more hydrophilic character and thicker ionomer film. | ||
| Key Words | ||
| fuel cell; PEMFC; hydrogen; oxygen reduction; portable application | ||
| Address | ||
| Paloma Ferreira-Aparicio and Antonio M. Chaparro: Department of Energy, CIEMAT, Avda. Complutense 40, 28040 Madrid, Spain | ||
