Ethanol oxidation on carbon supported platinum-rhodium bimetallic catalysts

被引：116

作者：

Bergamaski, Kleber ^{[2
]}

Gonzalez, Ernesto Rafael ^{[1
]}

Nart, Francisco Carlos ^{[1
]}

机构：

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

[2] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil

来源：

ELECTROCHIMICA ACTA | 2008年 / 53卷 / 13期

基金：

巴西圣保罗研究基金会;

关键词：

Pt-Rh catalysts; alcohol oxidation; reaction pathways; DEMS; HR-TEM;

D O I：

10.1016/j.electacta.2008.01.060

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

Platinum is the most investigated catalyst for the electrochemical oxidation of small organic molecules. This metal presents high overpotentials for the oxidation of organic compounds and the poisoning of active sites by strongly adsorbed intermediates, mainly CO, which decrease the efficiency of a direct alcohol fuel cell (DAFC). Ethanol is an ideal fuel for these DAFC systems due to its high energy density, but one of the problems with the electro-oxidation of this fuel is the low yield for the total oxidation to CO2. The purpose of the work reported here was to study the influence of the composition of Pt-Rh/C catalysts on the CO2 yields. In addition, using the differential electrochemical mass spectrometry (DEMS) technique, it is shown that Pt-Rh/C catalysts enhance the total ethanol oxidation with respect to pure Pt/C by driving the reaction via the CO2 route. The faradaic current efficiency for the oxidation of ethanol to CO2 increased from 0.08 on pure Pt/C to 0.5 on the Pt47Rh53/C catalyst at 0.7 V vs. RHE. It was concluded that electronic effects play a key role in the mechanism of ethanol oxidation on Pt-Rh/C electrodes. (c) 2008 Elsevier Ltd. All rights reserved.

引用

页码：4396 / 4406

页数：11

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