Fuel cell and electrochemical studies of the ethanol electro-oxidation in alkaline media using PtAuIr/C as anodes

Autor(es)

da Silva, Sirlane G. ; Fontes, Eric H. ; Assumpcao, Monica H. M. T. ; Linardi, Marcelo ; Spinace, Estevam ; Silva, Julio Cesar M. ; Neto, Almir O.

• Tipo de documento: Artigo Científico
• Fonte: IONICS; v. 23, n. 9, p. 2367-2376, SEP 2017.
• Citações Web of Science: 4

Resumo

Ethanol electro-oxidation reaction was investigated considering conventional electrochemical experiments in alkaline media, direct ethanol fuel cell (DEFC), and in situ ATR-FTIR. The working electrode/anodes were composed of monometallic Pt/C, Au/C, Ir/C, and trimetallic PtAuIr/C nanoparticles with atomic Pt/Au/Ir ratios of 40:50:10, 50:40:10, 60:30:10, 70:20:10, and 80:10:10. X-ray diffraction (XRD) suggests PtAuIr/C alloy formation, and according to transmission electron micrographs, the mean particle sizes are from 4 to 6 nm for all catalyst compositions. PtAuIr/C 40:50:10 showed the highest catalytic activity for ethanol electro-oxidation in the electrochemical experiments; using this material, the peak current density from ethanol electro-oxidation on cyclic voltammetry experiment was 50 mA per g of Pt, 3.5 times higher than that observed with Pt/C. The fuel cell performance was superior using all PtAuIr/C compositions than using Pt/C. Au/C and Ir/C presented very poor catalytic activity toward ethanol electro-oxidation. The improved results obtained using PtAuIr/C might be related to the OHads species formed at low overpotential on Ir and to the decrease on adsorption energy of poisoning intermediates on Pt sites, promoted by Au. (AU)

• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 14/09087-4 - Estudos sobre o uso do bioetanol em células a combustível do tipo PEMFC e SOFC
• Beneficiário: Marcelo Linardi
• Modalidade de apoio: Auxílio à Pesquisa - Temático