Ethanol oxidation reactions using SnO2@Pt/C as an electrocatalyst

Author(s)

Silva, J. C. M. ^[1] ; De Souza, R. F. B. ^[1] ; Parreira, L. S. ^[1] ; Teixeira Neto, E. ^[1] ; Calegaro, M. L. ^[2] ; Santos, M. C. ^[1]

Affiliation

^[1] Univ Fed Abc, CCNH, LEMN, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, Grp Mat Eletroquim & Metodos Eletroanalit, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 99, n. 1-2, p. 265-271, AUG 31 2010.
• Web of Science Citations: 62

Abstract

This paper presents a study on the ethanol oxidation reaction using SnO(2)@Pt/C core-shell structures as electrocatalysts. All the materials used, including Pt/C and PtSn/C E-tek, were 20% (w/w) metal on carbon. The formation of core-shell nanoparticles (SnO(2)@Pt/C) was measured by UV-vis spectrophotometry. X-ray diffraction measurements showed Pt (shell) diffraction patterns without influence from the SnO(2) core and without any shift in 2 theta values for Pt. The diameters of the core-shell particle structures, measured using high-resolution transmission electron microscopy images, were in the range of 3-16 nm. The electrochemical profile for SnO(2)@Pt/C in an acidic medium (H(2)SO(4) at a concentration of 0.5 mol L(-1)) was almost the same as the typical electrochemical behavior for Pt in an acidic medium. Furthermore, the onset potential for the ethanol oxidation reaction using SnO(2)@Pt/C was almost the same as that for PtSn/C E-tek (0.23 V versus the reversible hydrogen electrode). However, the mass current peak densities for ethanol oxidation were 50% higher on SnO(2)@Pt/C than on PtSn/C E-tek. In the polarization curve, the mass current density for ethanol oxidation was higher at all potentials for SnO(2)@Pt/C when compared to Pt/C and PtSn/C E-tek. At 0.5 V, the current mass density for ethanol oxidation on SnO(2)@Pt was 2.3 times of that for the same process on the commercial material. The electrocatalytic activity of SnO(2)@Pt/C for ethanol oxidation was associated with an increase in the electrochemically active surface area. However, an electronic effect should also be considered because the Pt shell changes its electronic structure in the presence of the foreign core. (C) 2010 Elsevier B.V. All rights reserved. (AU)

• 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