An STM study of phosphoric acid inhibition of the oxidation of HOPG and carbon catalyzed by alkali salts

被引：8

作者：

Wieber, A. P. ^{[1
]}

Guzman, J. E. ^{[1
]}

Wolf, E. E. ^{[1
]}

机构：

[1] Univ Notre Dame, Dept Chem & Biochem Engn, Notre Dame, IN 46556 USA

来源：

CARBON | 2006年 / 44卷 / 10期

关键词：

highly oriented graphite; oxidation; scanning tunneling microscopy; catalytic properties;

D O I：

10.1016/j.carbon.2005.12.028

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：

The role of phosphoric acid as an inhibitor in the oxidation of HOPG and as a neutralizer of alkali salt catalysts is examined using scanning tunneling microscopy, supported by thermogravimetric analysis of carbon powder samples. HOPG samples were oxidized in air primarily at 700 degrees C, with a few samples oxidized at 800 degrees C. Reaction time was 20 min. Powder samples were oxidized for 5 min at temperatures ranging from 500 degrees C to 900 degrees C and rates of oxidation were determined. STM images of impurity deposits and oxidized samples are presented and analyzed. Two alkali salts are examined, sodium hydroxide and potassium acetate, and both catalyze oxidation at 700 degrees C. Phosphoric acid proves to be an inhibitor at 700 degrees C but begins to lose its inhibiting effect at 800 degrees C. It also demonstrates neutralization of potassium acetate at 700 degrees C but results for NaOH/phosphoric acid mixtures are less conclusive. (c) 2006 Elsevier Ltd. All rights reserved.

引用

页码：2069 / 2079

页数：11

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