Electro-catalytic oxidation of CO on Pt catalyst supported on carbon nanotubes pretreated with oxidative acids

被引：82

作者：

Li, Li ^{[1
]}

Wu, Gang ^{[1
]}

Xu, Bo-Qing ^{[1
]}

机构：

[1] Tsinghua Univ, Dept Chem, Innovat Catalysis Program, Key Lab Organ Optoelect & Mol Engn, Beijing 100084, Peoples R China

来源：

CARBON | 2006年 / 44卷 / 14期

基金：

美国国家科学基金会;

关键词：

carbon nanotubes; chemically modified carbons; catalyst support; electro-chemical properties; chemical treatment;

D O I：

10.1016/j.carbon.2006.05.027

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Characteristics of nanosized Pt clectro-catalyst deposited on carbon nanotubes (CNTs) were studied with CO-stripping voltammogram and chronoamperometry measurements. The CNTs were pretreated by oxidation in HNO3, mixed HNO3 + H2SO4 and H2SO4 + K2Cr2O7 solution, respectively, to enable surface modification. Well-homogenized Pt particles (average size: approximate to 3 nm) were loaded onto the pretreated CNT samples by a modified colloidal method. TEM, BET, FTIR and XRD techniques were used to characterize the physicochemical properties of the pretreated CNT samples. In the electro-oxidation of CO, all the Pt/CNT samples showed lower on-set as well as peak potentials than the conventional Pt/XC-72 electro-catalyst, indicating that the Pt/CNT samples were more resistant to CO poisoning and could be superior anode clectro-catalyst for the proton exchange membrane fuel cells (PEMFCs). Moreover, we found that the pretreatment of CNTs in mixed HNO3 + H2SO4 Solution was very beneficial for the performance enhancement of Pt/CNT electro-catalyst; the catalyst obtained as such gave the lowest peak potential and the highest catalytic activity for the electro-oxidation of CO. Larger amount of oxygen-containing functional groups, higher percentage of mesopores, and higher graphitic crystallinity of the pretreated CNTs were considered crucial for the performance enhancement, e.g., by strengthening the interaction between Pt nanoparticles and the CNT support and enhancing the mass diffusion in the electro-chemical reaction. (c) 2006 Elsevier Ltd. All rights reserved.

引用

页码：2973 / 2983

页数：11

共 49 条

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