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

Ethanol electro-oxidation reaction was investigated considering conventional electrochemical experiments in alkaline media, direct ethanol fuel cell (DEFC), and in situ ATRFTIR. The working electrode/anodes were composed of monometallic Pt/C, Au/C, Ir/C, and trimetallic PtAuIr/C nanoparticles with a...

Full description

Access type:openAccess
Publication Date:2017
Main Author: SILVA, SIRLANE G. da
Other Authors: FONTES, ERIC H., ASSUMPÇAO, MONICA H.M.T., LINARDI, MARCELO, SPINACE, ESTEVAM, SILVA, JULIO C.M., O. NETO, ALMIR
Document type: Article
Online Access:http://repositorio.ipen.br:8080/xmlui/handle/123456789/27594
Portuguese abstract:Ethanol electro-oxidation reaction was investigated considering conventional electrochemical experiments in alkaline media, direct ethanol fuel cell (DEFC), and in situ ATRFTIR. 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.