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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Voltage Oscillations in a Polymer Electrolyte Membrane Fuel Cell with Pd-Pt/C and Pd/C Anodes

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Nogueira, Jessica Alves [1] ; Varela, Hamilton [1]
Total Authors: 2
[1] Univ Sao Paulo, Inst Chem Sao Carlos, POB 780, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: CHEMISTRYOPEN; v. 6, n. 5, p. 629-636, OCT 2017.
Web of Science Citations: 1

Polymer electrolyte membrane fuel cells (PEMFC) fed with H-2 contaminated with CO may exhibit oscillatory behavior when operated galvanostatically. The self-organization of the anodic overpotential is interesting because it can be accompanied by an increase in the average performance. Herein we report experimental studies of voltage oscillations that emerge in a PEMFC equipped with a Pd/C or PdPt/C anode and fed with H-2 contaminated with CO (100 ppm). We used on-line mass spectrometry to investigate how the mass fragments associated with CO2 and CO (m/z 44 and 28, respectively) varied with the voltage oscillations. Overall, we observed that oscillations in the anodic overpotential are in phase with that of the CO and CO, signals. This fact is consistent with an autonomous adsorption oxidation cyclic process. For both anodes, it has been observed that, in general, an increase in current density implies an increase in oscillatory frequency. By using CO stripping, we also discuss how the onset of CO oxidation is related to the maximum overpotential reached during a cycle, whereas the minimum overpotential can be associated with the catalytic activity of the electrode for H-2 oxidation. (AU)

FAPESP's process: 12/21204-0 - Temporal self-organization in electro-oxidation of small organic molecules: surface structure effect, water concentration and temperature
Grantee:Bruno Alarcon Fernandes Previdello
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 15/09295-9 - Dynamic behavior in low-temperature fuel cells based on oxidation of small organic molecules
Grantee:Jéssica Alves Nogueira
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
Grantee:Edson Antonio Ticianelli
Support type: Research Projects - Thematic Grants