Title
Different anode catalyst for high temperature polybenzimidazole-based direct ethanol fuel cells
Date Issued
11 January 2013
Access level
metadata only access
Resource Type
journal article
Author(s)
Universidade de São Paulo
Publisher(s)
Elsevier
Abstract
Five different bimetallic catalyst formulations (PtRu/C, PtSn/C, PtW/C, PtRh/C and PtOs/C) were prepared by reduction with sodium borohydride, and physico-chemically characterized by X-Ray Diffraction, Transmission Electron Microscopy, Temperature Programmed Reduction and X-Ray Photoelectron Spectroscopy. It was observed that in the case of the PtRu/C and PtRh/C a large fraction of the second metal enters the platinum lattice structure. The remaining metal, and in those catalysts in which no alloy was formed, its deposition was in a mixed metallic (Os) and/or oxide form, as TPR and XPS results displayed. Crystal sizes were in the range 3-5 nm, except for the case of the PtW/C in which there was a large agglomeration of platinum particles, as the TEM images confirmed. Electrochemical half-cell tests demonstrated the better performance of these bimetallic catalysts in terms of ethanol oxidation, with lower onset potential and larger current densities, particularly in the case of the PtOs/C, PtRu/C and PtRh/C materials, and to a lower extent in the case of the PtSn/C. Actual fuel cell tests at high temperature (150 and 200°C) confirmed the beneficial effects of increasing the temperature in terms of cell performance, with an increase in the performance, particularly in the cases of PtOs/C and PtRu/C. Finally, the product distribution was also assessed, observing a large conversion to CO2 by operating at high temperatures, particularly for PtRh/C at low current density, and for Pt/C at high current density (up to 35%), although acetaldehyde remained as the main oxidation product for all the catalysts. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Start page
620
End page
630
Volume
38
Issue
1
Language
English
OCDE Knowledge area
Bioproductos (productos que se manufacturan usando biotecnología), biomateriales, bioplásticos, biocombustibles, materiales nuevos bioderivados, químicos finos bioredivados
Electroquímica
Subjects
Scopus EID
2-s2.0-84871975020
Source
International Journal of Hydrogen Energy
ISSN of the container
03603199
Sponsor(s)
Authors want to thank the Fundação de Amparo à Pequisa do Estado de São Paulo (FAPESP) , the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) , and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the financial support. In particular, Thairo A. Rocha thanks CNPq (Proc. 160459/2011-7) for a Master Degree scholarship, José J. Linares also thanks FAPESP for a post-doctoral fellowship (Proc. 2010/07108-3). Authors also want to thank Istituto di Tecnologie Avanzate per l’Energia “Nicola Giordano” (ITAE-CNR, Italy) for the TEM images and the XPS experiments.
Sources of information:
Directorio de Producción Científica
Scopus