Surface structure and electronic properties of Pt-Fe/C nanocatalysts and their relation with catalytic activity for oxygen reduction

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Data

2010-05-15

Autores

Malheiro, A. R. [UNESP]
Perez, J. [UNESP]
Villullas, Hebe de Las Mercedes [UNESP]

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Editor

Elsevier B.V.

Resumo

In this work, physical and catalytic properties of Pt-Fe/C nanocatalysts of nominal compositions Pt;Fe 70:30 and 50:50, prepared by a polyol process using a long-chain diol as reducer (hexadecanediol) and oleic acid and oleylamine as stabilizers, are reported. As-prepared materials have very small particle size (2.2 nm), narrow particle size distribution, and homogeneous dispersion on the carbon support. The average compositions determined by energy dispersive X-ray analysis are Pt(75)Fe(25)/C and Pt(60)Fe(40)/C. Data for samples submitted to heat treatment in hydrogen atmosphere to induce Pt surface segregation are also presented. X-ray diffraction and transmission electronic microscopy are used to examine all as-prepared and heat-treated catalysts. Electronic properties are analyzed based on in situ dispersive X-ray absorption spectroscopy data. Measurements of electrocatalytic activity for oxygen reduction show that all Pt-Fe/C have electrocatalytic activities superior to that of Pt/C. Nanocatalysts with a Pt-rich surface have an enhanced performance for the reduction of oxygen but measurements carried out in methanol containing solutions show that Pt-enriched surfaces have an inferior methanol tolerance. (C) 2009 Elsevier B.V. All rights reserved.

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Palavras-chave

Electrocatalyst, Oxygen reduction reaction, Nanostructured materials, Pt-based nanoparticles

Como citar

Journal of Power Sources. Amsterdam: Elsevier B.V., v. 195, n. 10, p. 3111-3118, 2010.