Electrocatalytic Activity of Platinum-Niobium Nanoparticles for Ethanol Oxidation

Autor(es)

Rocha, Thairo A. ^[1] ; Linares, Jose J. ^[1] ; Colmati, Flavio ^[2] ; Ciapina, Eduardo G. ^[1] ; Gonzalez, Ernesto R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Fed Goias, Inst Quim, Goiania, Go - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Electrochemical Society; v. 159, n. 10, p. F650-F658, 2012.
• Citações Web of Science: 6

Resumo

Three nanostructured platinum-niobium supported on Vulcan XC-72R carbon black materials were prepared as catalysts for the ethanol electroxidation: (i) deposition of platinum and niobium on Vulcan XC-72R carbon black, (ii) platinum decorated on a mixture of commercial amorphous Nb2O5/carbon black, and (iii) the same than ii but using crystalline Nb2O5, by reduction of the precursors with sodium borohydride in ethanol. All the catalysts showed platinum crystal sizes in the range of 3-4 nm, with no or little modification of the lattice parameter. The analyses of the electronic structure from the XANES region of the XAS spectra displayed some interactions between platinum and niobium, despite the niobium was primarily in the form of pentoxide in all the catalysts. CO stripping exhibited a promising low onset potential and a large current density, especially in the case of the deposited catalyst. Ethanol electroxidation experiments revealed that the Pt-Nb(2)O(5)crystalline/C generated the largest current. However it was not effective to completely oxidize ethanol, leading to acetic acid as the main product. In this sense, the highest efficiency for the complete oxidation of ethanol was obtained for the deposited catalyst. These results were interpreted in terms of the physico-chemical characteristic displayed by the different catalysts. (C) 2012 The Electrochemical Society. {[}DOI: 10.1149/2.040210jes] All rights reserved. (AU)

• Processo FAPESP: 10/07108-3 - Desenvolvimento de estratégias para aumentar a eficiência da reação de oxidação de etanol pelo mecanismo de 12 elétrons, dando CO2 como produto, no contexto das células a combustível de etanol direto
• Beneficiário: José Joaquín Linares León
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 10/02905-2 - Síntese, caracterização e avaliação de desempenho frente a reação de redução de oxigênio de eletrocatalisadores nanoestruturados preparados por métodos coloidais.
• Beneficiário: Eduardo Gonçalves Ciapina
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado