Effect of molten carbonate composition on oxygen reduction under pressurized conditions: cyclic voltammetry and equivalent circuit analysis

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• 作者：M. Mohamedi ; Y. Hisamitsu ; Y. Ono ; T. Itoh and I. Uchida
• 关键词：molten carbonate ; oxygen reduction ; pressurization ; solubility
• 刊名：Journal of Applied Electrochemistry
• 出版年：2000
• 出版时间：2000
• 年：2000
• 卷：30
• 期：12
• 页码：1397-1404
• 全文大小：162 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Electrochemistry
  Physical Chemistry
  Industrial Chemistry and Chemical Engineering
  
• 出版者：Springer Netherlands
• ISSN：1572-8838

文摘

The oxygen reduction mechanism was investigated in carbonate melts of variable composition ranging from the eutectics Li–K, Li–Na to ternary Li–Na–K melts. The effect of pressure on electrode kinetics was also examined. Cyclic voltammetry, convolution voltammetry and electrochemical impedance spectroscopy have shown that oxygen reduction is mass-transfer limited in all melt compositions investigated. It was also found that pressurizing increased the concentration of oxygen electroactive species. To gain information about the reaction mechanism, the impedance spectra have been fitted to four possible equivalents circuits: (i) Randles circuit, (ii) Randles circuit extended by a parallel RC circuit due to film formation, (iii) Gerisher (homogeneous reaction) impedance, and (iv) Modified Randles circuit. The discussion of the results is based on careful analysis of fit quality and meaningfulness of fit parameters.