PtSnCe/C electrocatalysts for ethanol oxidation: DEFC and FTIR "in-situ" studies

Author(s)

De Souza, R. F. B. ; Parreira, L. S. ; Silva, J. C. M. ; Simoes, F. C. ; Calegaro, M. L. ; Giz, M. J. ; Camara, G. A. ; Neto, A. O. ; Santos, M. C.

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 36, n. 18, p. 9-pg., 2011-09-01.

Abstract

The ethanol oxidation reaction (EOR) was investigated using PtSnCe/C electrocatalysts in different mass ratios (72:23:5, 68:22:10 and 64:21:15) that were prepared by the polymeric precursor method. Transmission electron microscopy (TEM) showed that the particles ranged in size from approximately 2 to 5 nm. Changes in the net parameters observed for Pt suggest the incorporation of Sn and Ce into the Pt crystalline network with the formation of an alloy between Pt, Sn and/or Ce. Among the PtSnCe catalysts investigated, the 68:22:10 composition showed the highest activity toward ethanol oxidation, and the current time curves obtained in the presence of ethanol in acidic media showed a current density 50% higher than that observed for commercial PtSn/C (E-Tek). During the experiments performed on single direct ethanol fuel cells, the power density for the PtSnCe/C 68:22:10 anode was nearly 40% higher than the one obtained using the commercial catalyst. Data from Fourier transform infrared (FTIR) spectroscopy showed that the observed behavior for ethanol oxidation may be explained in terms of a double mechanism. The presence of Sn and Ce seems to favor CO oxidation, since they produce an oxygen-containing species to oxidize acetaldehyde to acetic acid. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 10/03037-4 - Degradation mechanism study of the cathode and anode catalyst for direct ethanol fuel cell
• Grantee: Fernando Carmona Simões
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 10/07831-7 - Synthesis and characterization of PtSn/C, PtIr/C and PtSnIr for the study of the mechanism of ethanol electrochemical oxidation using spectroscopic in situ techniques
• Grantee: Júlio César Martins da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/09145-6 - Study of ethanol electrochemical oxidation mechanism on PtSn, PtCe and PtSnCe using in-situ spectroscopic techniques
• Grantee: Rodrigo Fernando Brambilla de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 10/16511-6 - Energy generation from biofuel using nanostructures
• Grantee: Mauro Coelho dos Santos
• Support Opportunities: Regular Research Grants