Kinetic study of CO oxidation on step decorated Pt(111) vicinal single crystal electrodes

被引：12

作者：

Chen, Qing-Song ^{[1
,2
]}

Feliu, Juan M. ^{[1
]}

Berna, Antonio ^{[1
]}

Climent, Victor ^{[1
]}

Sun, Shi-Gang ^{[2
]}

机构：

[1] Univ Alicante, Inst Electrochem, E-03080 Alicante, Spain

[2] Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China

来源：

ELECTROCHIMICA ACTA | 2011年 / 56卷 / 17期

关键词：

Pt single crystal electrodes; Stepped surfaces; Adatom step decoration; CO oxidation kinetics; Langmuir-Hinshelwood model; PERCHLORIC-ACID MEDIA; MONOLAYER OXIDATION; PLATINUM NANOPARTICLES; ELECTROCHEMICAL OXIDATION; ADSORPTION BEHAVIOR; ADLAYER OXIDATION; SURFACE; ELECTROOXIDATION; MECHANISM; ELECTROCATALYSIS;

D O I：

10.1016/j.electacta.2011.04.101

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

In this work, surface modification at atomic level was applied to study the reactivity of step sites on platinum single crystal surfaces. Stepped platinum single crystal electrodes with (1 1 1) terraces separated by monoatomic step sites with different symmetry were decorated with irreversibly adsorbed adatoms, without blocking the terrace sites, and characterized in 0.1 M HClO4 solution. The kinetics of CO oxidation on the different platinum single crystal planes as well as on the step decorated surfaces has been studied using chronoamperometry. The apparent rate constants, which were determined by fitting the experimental data to a mean-field model, decrease after the steps of platinum single crystal electrodes have been blocked by the adatoms. This behavior indicates that steps are active sites for CO oxidation. Tafel slopes measured from the potential dependence of the apparent rate constants of CO oxidation were similar in all cases. This result demonstrates that the electrochemical oxidation of the CO adlayer on all the surfaces follows the same Langmuir-Hinshelwood model, irrespectively of step modification. (C) 2011 Elsevier Ltd. All rights reserved.

引用

页码：5993 / 6000

页数：8