Well-Alloyed PtFe/C Nanocatalysts of Controlled Composition and Same Particle Size: Oxygen Reduction and Methanol Tolerance

Autor(es)

Malheiro, Arthur R. ^[1] ; Perez, Joelma ^[1] ; Villullas, H. Mercedes ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Quim, Dept Quim Fis, BR-14801970 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Electrochemical Society; v. 156, n. 1, p. B51-B58, 2009.
• Citações Web of Science: 34

Resumo

A study of the effect of iron concentration on the electrocatalysis of oxygen reduction reaction (ORR) on well-alloyed carbon-supported PtFe nanocatalysts with a controlled iron content and the same particle size is presented. To obtain the catalysts for this study, PtFe nanoparticles of different compositions were first obtained in a colloidal state in sodium bis(2-ethylhexyl)sulfosuccinate (AOT)+n-butanol/n-heptane/water microemulsions and subsequently supported in high surface area carbon powder. Transmission electron microscopy evidenced that all PtFe/C nanocatalysts prepared are monodispersed and have nearly the same average particle size. X-ray diffraction studies showed that the lattice parameter of these PtFe/C catalysts varies linearly with iron content up to 50% (in atoms), while the compositions of the alloyed phases estimated by using Vegard's law are almost identical to the nominal values, indicating a high degree of alloying. The electrocatalytic activity for ORR of these catalysts was studied using the rotating disk electrode technique in O(2) saturated 0.5 mol L(-1) H(2)SO(4) solutions, while methanol tolerance was evaluated from curves taken in acid solutions containing 0.1 mol L(-1) methanol. The results reported here reflect the dependence of the electrocatalytic activity for the ORR on iron concentration in the absence of particle size effects and metal segregation. (AU)

• Processo FAPESP: 04/15570-8 - Preparacao e caracterizacao de nanoparticulas metalicas e bimetalicas coloidais para eletrocatalise.
• Beneficiário: Hebe de las Mercedes Villullas
• Modalidade de apoio: Auxílio à Pesquisa - Regular