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

JOURNAL OF POWER SOURCES

卷:195

Article

Malheiro, A. R.¹  Perez, J.¹  Villullas, H. M.¹ 

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

关键词: Electrocatalyst;    Oxygen reduction reaction;    Nanostructured materials;    Pt-based nanoparticles;   

DOI  :  10.1016/j.jpowsour.2009.11.096

来源: Elsevier

【 摘 要 】

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 Pt75Fe25/C and Pt60Fe40/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.

【 授权许可】

Free