An Electrochemical Impedance Spectroscopy Study of Polymer Electrolyte Membrane Fuel Cells Electrocatalyst Single Wall Carbon Nanohorns-Supported

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Brandão, L. (Author) FEUP; Boaventura, M. (Author) FEUP; Passeira, C. (Author) FEUP; Gattia, D.M. (Author) FEUP; Marazzi, R. (Author) FEUP; Antisari, M.V. (Author) FEUP; Mendes, A. (Author) FEUP

Journal

Title: Journal of Nanoscience and Nanotechnology

Vol. 11

Pages: 9016-9024

ISSN: 1533-4880

Publisher: American Scientific Publishers

Indexing

ISI Web of Knowledge - 13 Citations

ISI Web of Science

Scopus - 13 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-002-KNZ

DOI: 10.1166/jnn.2011.3466

Abstract (EN): Electrochemical impedance spectroscopy (EIS) was used to study the polymer electrolyte membrane fuel cells (PEMFC) performance when using single wall carbon nanohorns (SWNH) to support Pt nanoparticles. Additionally, as-prepared and oxidized SWNH Pt-supports were compared with conventional carbon black. Two different oxidizing treatments were considered: oxygen flow at 500 degrees C and reflux in an acid solution at 85 degrees C. Both oxidizing treatments increased SWNH surface area; oxygen treatment increased surface area 4 times while acid treatment increased 2.6 times. The increase in surface area should be related to the opening access to the inner tube of SWNH. Acid treatment of SWNH increased chemical fragility and decreased electrocatalyst load in comparison with as-prepared SWNH. On the other hand, the oxygen treated SWNH sample allowed to obtain the highest electrocatalyst load. The use of as-prepared and oxygen treated SWNH showed in both cases catalytic activities 60% higher than using conventional carbon black as electrocatalyst support in PEMFC. Moreover, EIS analysis indicated that the major improvement in performance is related to the cathode kinetics in the as-prepared SWNH sample, while concerning the oxidized SWNH sample, the improvements are related to the electrokinetics in both anode and cathode electrodes. These improvements should be related with differences in the hydrophobic character between SWNH and carbon black.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9