The electrooxidation of carbon monoxide on unsupported Pt agglomerates

被引：32

作者：

Ciapina, Eduardo G. ^{[1
]}

Santos, Sydney F. ^{[2
]}

Gonzalez, Ernesto R. ^{[1
]}

机构：

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

[2] Univ Fed Abc, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, BR-09210170 Santo Andre, SP, Brazil

来源：

JOURNAL OF ELECTROANALYTICAL CHEMISTRY | 2010年 / 644卷 / 02期

基金：

巴西圣保罗研究基金会;

关键词：

CO electrooxidation; Unsupported Pt nanoparticles; CO-stripping; Electrocatalysis; Structural characterization; CO MONOLAYER OXIDATION; RAY-ABSORPTION SPECTROSCOPY; HIGH-SURFACE-AREA; PARTICLE-SIZE; PLATINUM; NANOPARTICLES; ELECTROCATALYSTS; ELECTRODES; ELECTROCHEMISTRY; ADSORPTION;

D O I：

10.1016/j.jelechem.2009.09.022

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

This work presents some insights on the CO electrooxidation on unsupported Pt nanoparticles in terms of the role played by particle size, surface crystallography, and defects, based on the results of structural and electrochemical characterization. The electrochemical properties were probed through potentiodynamic and potentiostatic CO-stripping experiments conducted in two samples of unsupported Pt nanoparticles, "Pt (FAM)", synthesized by chemical reduction, and "Pt (J-M)", a commercial material. Experiments were carried out in 0.1 mol L-1 HClO4 at room temperature (similar to 25 degrees C). The structural, morphological, and electronic features of these materials were investigated by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and X-ray absorption Fine structure spectroscopy (XAFS), respectively. The XRD analysis indicated texture (preferential orientation) effects, in addition to a larger crystallite size for the Pt (FAM) sample. TEM images revealed a large degree of agglomeration and suggested a larger particle size for Pt (FAM) than for Pt (J-M), in addition to morphological differences between them. XAFS analysis suggested differences in the electronic structure of the materials probably caused by size effects. Cyclic voltammetry results in 0.5 mol L-1 H2SO4 were obtained and discussed in terms of the surface crystallography and also on possible particle-size effects. Both potentiodynamic and potentiostatic CO-stripping experiments revealed different electrochemical behaviors between the unsupported Pt samples, evidencing the extremely structure-sensitive character of the CO electrochemical oxidation. (C) 2009 Elsevier B.V. All rights reserved.

引用

页码：132 / 143

页数：12

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