Thermodynamic, thermomechanical, and electrochemical evaluation of CsHSO4

被引：54

作者：

Uda, T ^{[1
]}

Boysen, DA ^{[1
]}

Haile, SM ^{[1
]}

机构：

[1] CALTECH, Pasadena, CA 91125 USA

来源：

SOLID STATE IONICS | 2005年 / 176卷 / 1-2期

关键词：

fuel cell; superprotonic transition; thermodynamics; solid acid; proton conductor;

D O I：

10.1016/j.ssi.2004.04.017

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：

A thermodynamic analysis of CsHSO4 in oxygen and hydrogen atmospheres has been carried out. In an oxygen atmosphere, the phase relationship for the dehydration of CsHSO4 as a function of H2O partial pressure was established. It is concluded that CsHSO4 is stable in a humidified oxygen atmosphere, pH(2)O = 0.03 atm, up to 170 degreesC. However, in hydrogen atmospheres, it was affirmed that CsHSO4 is reduced to H2S and Cs2SO4. Electromotive force (EMF) measurements in a humidified oxygen concentration cell, pH(2)O = 0.03 atm confirmed the ionic nature of the charge-carrying species. Upon thermal cycling, the voltage obtained from the high temperature phase (T = 149 degreesC) remained unchanged for over 85 h of measurement. The volume change upon transformation to the superprotonic phase, as directly measured by high temperature X-ray powder diffraction, is +0.54%. These results demonstrate not only the stability of CsHSO4 in oxygen but also the viability of solid acid-based electrochemical devices that would likely be subjected to thermal cycling during operation. (C) 2004 Elsevier B.V. All rights reserved.

引用

页码：127 / 133

页数：7

共 14 条

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