Giant multilayer electrocatalytic effect investigation on Pt/Bi/Pt nanostructured electrodes towards CO and methanol electrooxidation

Autor(es)

Freitas‚ RG ; Pereira‚ EC

• Tipo de documento: Artigo Científico
• Fonte: Electrochimica Acta; v. 55, n. 26, p. 7622-7627, 2010.

Resumo

This work describes CO and methanol electrooxidation over Bi/Pt 1.2:1.2 or 10:10 ML electrodeposited on a bulk platinum substrate. It could be observed in a blank solution that the same features for bulk Pt and Pt/Bi/Pt MM and the hydrogen region were overlaid. The electroactive areas, calculated using the hydrogen desorption method, are the same for both bulk Pt and Pt/Bi/Pt MM electrodes. This is in agreement with AFM images and RMS values, which were the same for bulk Pt and Pt/Bi/Pt MM electrodes. CO stripping voltammograms showed a shift in the anodic peak potential towards the negative direction of 138 and 197 mV for Pt/Bi/Pt 10:10 and 1.2:1.2 ML, respectively, in comparison to bulk Pt. Moreover, for methanol electrooxidation the Pt/Bi/Pt 1.2:1.2 ML electrodes presented an enhancement of 315% and 22 times in the peak current density compared to bulk Pt using cyclic voltammetry and chronoamperometry techniques respectively. Using electrochemical impedance spectroscopy, it was possible to observe the lowest resistance charge transfer for Pt/Bi/Pt 1.2:1.2 ML compared to Pt/Bi/Pt 10:10 ML and bulk Pt respectively. We designate the Pt/Bi/Pt MM electrodes as a giant multilayer electrocatalytic (GME) system, due to their enhanced electrocatalytical properties. (C) 2009 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 05/04708-1 - Preparacao e caracterizacao de multicamadas metalicas para eletrocatalise.
• Beneficiário: Renato Garcia de Freitas Sobrinho
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 03/09933-8 - Núcleo de Excelência em Materiais Nanoestruturados Fabricados Eletroquimicamente
• Beneficiário: Ernesto Chaves Pereira de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Programa PRONEX - Temático