TY - JOUR
T1 - Thermodynamic investigations of a hydrogen electrode reaction in a molten LiCl-KCl-LiH system
AU - Nakajima, Hironori
AU - Nohira, Toshiyuki
AU - Ito, Yasuhiko
PY - 2002/5
Y1 - 2002/5
N2 - The equilibrium potential of the H2/H- couple has been measured in a molten LiCl-KCl-LiH system at 643-883 K. The Nernst relation holds for the potential at hydrogen pressure, pH2, of 0.1-1.0 atm and H- ion concentration, XH-, of 0.002-0.080 (anion fraction). The standard formal potential of H2/H-, EH2/H- 0′, is evaluated to be 0.258 ± 0.002 V (vs. Li+/Li) (pH2 = 1 atm, XH- = 1) at 673 K. EH2/H- 0′ changes linearly with temperature at 643-883 K, having the gradient of -0.575 ± 0.011 mV K-1. Thermodynamic quantities for formation of LiH in the melt are also estimated. When the activity coefficient of H- ion, γH-, is defined as unity in pure liquid LiH (XH- = 1), γH- in the dilute H- region (0.002 ≤ XH- ≤ 0.080) is evaluated to be 7.1.
AB - The equilibrium potential of the H2/H- couple has been measured in a molten LiCl-KCl-LiH system at 643-883 K. The Nernst relation holds for the potential at hydrogen pressure, pH2, of 0.1-1.0 atm and H- ion concentration, XH-, of 0.002-0.080 (anion fraction). The standard formal potential of H2/H-, EH2/H- 0′, is evaluated to be 0.258 ± 0.002 V (vs. Li+/Li) (pH2 = 1 atm, XH- = 1) at 673 K. EH2/H- 0′ changes linearly with temperature at 643-883 K, having the gradient of -0.575 ± 0.011 mV K-1. Thermodynamic quantities for formation of LiH in the melt are also estimated. When the activity coefficient of H- ion, γH-, is defined as unity in pure liquid LiH (XH- = 1), γH- in the dilute H- region (0.002 ≤ XH- ≤ 0.080) is evaluated to be 7.1.
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U2 - 10.1149/1.1462876
DO - 10.1149/1.1462876
M3 - Article
AN - SCOPUS:0036112076
VL - 5
JO - Electrochemical and Solid-State Letters
JF - Electrochemical and Solid-State Letters
SN - 1099-0062
IS - 5
ER -