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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.)

Different anode catalyst for high temperature polybenzimidazole-based direct ethanol fuel cells

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Author(s):
Linares, Jose J. [1] ; Rocha, Thairo A. [1] ; Zignani, Sabrina [1] ; Paganin, Valdecir A. [1] ; Gonzalez, Ernesto R. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 38, n. 1, p. 620-630, JAN 11 2013.
Web of Science Citations: 24
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 degrees 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. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 10/07108-3 - Electrocatalysis IV: fundamental and applied aspects of electrocatalytic processes, bio-electrocatalysis and kinetic instabilities
Grantee:José Joaquín Linares León
Support Opportunities: Scholarships in Brazil - Post-Doctoral