Stability and Characterization of Oxygen Species in Alkali Molten Carbonate: A Thermodynamic and Electrochemical Approach
Stability and Characterization of Oxygen Species in Alkali Molten Carbonate: A Thermodynamic and Electrochemical Approach
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DOI：
10.1149/1.2220995
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发表时间：
1993-11
影响因子：
3.9
通讯作者：
M. Cassir;G. Moutiers;J. Devynck
中科院分区：
文献类型：
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作者：
M. Cassir;G. Moutiers;J. Devynck
近20年来，碳酸盐熔液燃料电池的化学和电化学性能的研究得到了广泛的讨论，这是优化碳酸盐熔液燃料电池性能的需要。在不同的氧酸水平和温度下，研究了几种碱熔融碳酸盐中还原氧的稳定性和电化学行为。理论预测和实验结果吻合良好，表明在Na-K、Li-Na、Li-K和Li-Na- k熔体中，过氧化物只能在碱性介质中稳定。超氧化物在含锂碳酸盐中不稳定，在微碱性条件下可以在Na-K中稳定。通过伏安法和卷积电位扫描技术对过氧化/氧化物和超氧化物/氧化物氧化还原体系进行了表征。结果表明，CO[sub 2]不参与超氧化物和过氧化物的速率决定还原机制。测定了各被引体系（D, [delta], E[sup 0], E[sub 1/2]）的电化学参数以及还原氧的溶解度。
The study of the chemical and electrochemical properties of molten carbonate has been widely discussed in the last 20 years because of the necessity for optimizing molten carbonate fuel cell (MCFC) performance. The stability and electrochemical behavior of reduced oxygen species were investigated in several alkali molten carbonates at different oxoacidity levels and temperatures. Theoretical predictions and experimental results were in good agreement and show that, in Na-K, Li-Na, Li-K, and Li-Na-K melts, peroxide species can only be stabilized in basic media. Superoxide species, unstable in lithium-containing carbonate, can be stabilized in Na-K under slightly basic conditions. Peroxide/oxide and superoxide/oxide redox systems were characterized by voltammetric and convolution potential sweep techniques. It was shown that CO[sub 2] does not participate in the rate-determining reduction mechanisms of both superoxide and peroxide species. Electrochemical parameters relative to the cited systems (D, [delta], E[sup 0], E[sub 1/2]), as well as the solubility of reduced oxygen species were determined.