Influence of toluene contamination at the hydrogen Pt/C anode in a proton exchange membrane fuel cell
2010 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 0019-4686, Vol. 55, no 26, 7643-7651 p.Article in journal (Refereed) Published
For fuel cells run on hydrogen reformate, traces of hydrocarbon contaminants in the hydrogen gas may be a concern for the performance and lifetime of the fuel cell. This study focuses on the influence of low concentrations of toluene on the adsorption and deactivation chemistry in a proton exchange membrane (PEM) fuel cell. For this purpose cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques were employed. Results from adsorption and desorption (by oxidation or reduction) experiments performed in a humidified nitrogen or hydrogen flow in a fuel cell test cell with a mass spectrometer system connected to the outlet are presented. The influence of adsorption potential, temperature, and humidity are discussed. The results show that toluene adsorbs on the catalyst surface in a broad potential window, up to at least 0.85 V versus RHE at 80 degrees C. Adsorbed toluene oxidizes to CO2 with peak potentials above 1.0V for temperatures below 95 degrees C. Some desorption of toluene (or reduced products) may take place at potentials below 0V. In a hydrogen flow, toluene contamination in per mille concentrations leads to a continuous growth of the charge transfer resistance, while a 10-fold dilution of the toluene concentration resulted in a low and constant charge transfer resistance even for longer exposures. This indicates that a competition between toluene and hydrogen may take place on the active platinum surface at the anode.
Place, publisher, year, edition, pages
2010. Vol. 55, no 26, 7643-7651 p.
Toluene contamination, PEMFC, Anode, Cyclic voltammetry, Electrochemical impedance spectroscopy
IdentifiersURN: urn:nbn:se:kth:diva-29193DOI: 10.1016/j.electacta.2009.11.048ISI: 000283209800015ScopusID: 2-s2.0-77957109684OAI: oai:DiVA.org:kth-29193DiVA: diva2:393887
QC 201102012011-02-012011-01-272016-10-07Bibliographically approved