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

Autor(es)

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]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 99, n. 1-2, p. 265-271, AUG 31 2010.
• Citações Web of Science: 62

Resumo

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)

• Processo FAPESP: 05/59992-6 - Materiais nanoestruturados: eletrocatálise e membranas de óxidos
• Beneficiário: Mauro Coelho dos Santos
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 08/58788-4 - Eletrocatálise das reações de oxidação de metanol e etanol utilizando-se nanomateriais baseados em ligas metálicas de PtSn
• Beneficiário: Luanna Silveira Parreira
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 09/09145-6 - Estudo do mecanismo de oxidação eletroquímica de etanol com eletrocatalisadores de PtSn, PtCe e PtSnCe utilizando técnicas espectroscópicas in-situ
• Beneficiário: Rodrigo Fernando Brambilla de Souza
• Modalidade de apoio: Bolsas no Brasil - Doutorado