CO and methanol electrooxidation on Pt/Ir/Pt multilayers electrodes

被引：43

作者：

Freitas, R. G. ^{[1
]}

Antunes, E. P. ^{[1
]}

Pereira, E. C. ^{[1
]}

机构：

[1] Univ Fed Sao Carlos, NANOFAEL, LIEC, Dept Quim, BR-13565905 Sao Carlos, SP, Brazil

来源：

ELECTROCHIMICA ACTA | 2009年 / 54卷 / 07期

基金：

巴西圣保罗研究基金会;

关键词：

Nanostructured electrodes; Electrocatalysis; Multilayers; POLYMERIC PRECURSOR METHOD; SMALL ORGANIC-MOLECULES; TIME FTIR SPECTROSCOPY; FUEL-CELL CATALYSTS; METALLIC BILAYER; ELECTROCATALYTIC OXIDATION; MAGNETIC-PROPERTIES; CARBON-MONOXIDE; AC-IMPEDANCE; FORMIC-ACID;

D O I：

10.1016/j.electacta.2008.07.073

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

This work describes the CO and methanol electrooxidation over an Ir/Pt bilayer electrodeposited on a platinum polycrystalline substrate. In the blank acidic solution it was observed that the electrochemical behavior of both the polycrystalline Pt and Pt/Ir/Pt nanostructured electrodes were very similar. The electroactive area, calculated using the hydrogen desorption method, are the same for both materials. In order to investigate the effect of the thickness change of Ir interlayer, two different samples were prepared. One with 1 Ir monolayer and the second with 3 monolayers thick. CO stripping voltammograms showed a shift in the anodic peak potential towards the negative direction of 160 and 180 mV for Pt/Ir/Pt 3:1 and 1:1 ML, respectively, compared to polycrystalline Pt. Besides, for methanol electrooxidation, the Pt/Ir/Pt electrodes presented an increase of 170% in the peak current density compared to polycrystalline Pt. These results are in agreement with the calculated activation energies which were 31.5, 39.0 and 43.5 kJ mol(-1) for Pt/Ir/Pt 1:1, 3:1 ML and polycrystalline Pt electrodes, respectively. Using the electrochemical impedance spectroscopy, surprisingly, the Pt/Ir/Pt electrodes, did not exhibit the inductive arc which means that the poisoning of the electrode surface is not important in this case. (C) 2008 Elsevier Ltd. All rights reserved.

引用

页码：1999 / 2003

页数：5

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