The Rapid Formation of La(OH)3 from La2O3 Powders on Exposureto Water Vapor

被引：144

作者：

Fleming, Peter ^{[1
]}

Farrell, Richard A. ^{[1
]}

Holmes, Justin D. ^{[1
]}

Morris, Michael A. ^{[1
]}

机构：

[1] Natl Univ Ireland Univ Coll Cork, Dept Chem, Cork, Ireland

来源：

JOURNAL OF THE AMERICAN CERAMIC SOCIETY | 2010年 / 93卷 / 04期

关键词：

LANTHANUM HYDROXIDE; TRANSFORMATION;

D O I：

10.1111/j.1551-2916.2009.03564.x

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The reactivity of various lanthana powders in air was studied. The materials rapidly hydroxylate to form a stable hydroxide, La(OH)(3), at room temperature. Smaller amounts of an oxycarbonate species (La2O2CO3) are also observed following air exposure. This oxycarbonate phase is stable to hydroxylation. All oxide materials synthesized here show rapid reactions so that 24 h of exposure to atmosphere is generally sufficient to cause complete hydroxylation at room temperature. The rate of reaction was related to the crystallite size as determined by XRD. The reaction was found to follow a two-stage kinetic process, a relatively slow surface reaction followed by a rapid bulk reaction. The relevance of the reactivity of these powders is discussed.

引用

页码：1187 / 1194

页数：8

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