Preparation of Pt/C-In2O3 center dot SnO2 Electrocatalysts by Borohydride Reduction Process for Ethanol Electro-Oxidation

Author(s)

Henrique, R. S. ^[1] ; De Souza, R. F. B. ^[2] ; Silva, J. C. M. ^[2] ; Ayoub, J. M. S. ^[1] ; Piasentin, R. M. ^[1] ; Linardi, M. ^[1] ; Spinace, E. V. ^[1] ; Santos, M. C. ^[2] ; Neto, A. O. ^[1]

Affiliation

^[1] CNEN SP, IPEN, BR-05508900 Sao Paulo - Brazil

^[2] UFABC Univ Fed ABC, LEMN, CCNH, BR-09210170 Santo Andre, SP - Brazil

• Document type: Journal article
• Source: International Journal of Electrochemical Science; v. 7, n. 3, p. 2036-2046, MAR 2012.
• Web of Science Citations: 24

Abstract

Pt/C-In2O3 center dot SnO2 electrocatalysts was prepared in the single step using H2PtCl6 center dot 6H(2)O as metal sources, sodium borohydride as reducing agent and a physical mixture of 85% Vulcan Carbon XC72 and 15% In2O3 center dot SnO2 (indium tin oxide - ITO) as support. The electrocatalysts were characterized by X-ray diffraction and transmission electron microscopy, cyclic voltammetry, chronoamperommetry, Attenuated Total Reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and performance test on direct ethanol fuel cell. The diffractograms of the Pt/C showed four peaks associated the face-centered cubic (fcc) structure of platinum, while that Pt/C-In2O3 center dot SnO2 electrocatalysts showed peaks associated the face-centered cubic (fcc) structure of platinum and several others peaks associated with Indium-doped SnO2 (ITO) used as supports. Transmission electron microscopy for Pt/C and Pt/CIn2O3 center dot SnO2 electrocatalysts showed that the metal particles were homogeneously distributed over the support with particles size of 3.0 nm. The electrochemical studies (cyclic voltammetry and chronoamperometry) showed that Pt/C-In2O3 center dot SnO2 had superior performance for ethanol electro-oxidation in comparison with Pt/C in all potential range of interest (0.05-0.9V). The experiments at 100 degrees C on single direct ethanol fuel cells showed that the power density for the Pt/C-In2O3 center dot SnO2 was nearly 400% higher than the one obtained using Pt/C indicating an improved tolerance to intermediate adsorbed. The data from Fourier transform infrared spectroscopy showed that the addition of C-In2O3 center dot SnO2 to Pt favors a more complete oxidation of the ethanol molecule, where In2O3 center dot SnO2 provide an oxygen-containing species to oxidize acetaldehyde to acetic acid. (AU)

• FAPESP's process: 10/16511-6 - Energy generation from biofuel using nanostructures
• Grantee: Mauro Coelho dos Santos
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/18246-0 - Preparation of PD binary and ternary electrocatalysts by borohydride reduction for alcohol electro-oxidation in alkaline medium
• Grantee: Almir Oliveira Neto
• Support Opportunities: Regular Research Grants
• 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