The Minimum Electrolytic Energy Needed To Convert Carbon Dioxide to Carbon by Electrolysis in Carbonate Melts

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• 作者：Jiawen Ren ; Jason Lau ; Matthew Lefler ; Stuart Licht
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：October 15, 2015
• 年：2015
• 卷：119
• 期：41
• 页码：23342-23349
• 全文大小：441K
• ISSN：1932-7455

文摘

One pathway to remove the greenhouse gas carbon dioxide to mitigate climate change is by dissolution and electrolysis in molten carbonate to produce stable, solid carbon. This study determines critical knowledge to minimize the required electrolysis energy, the reaction stoichiometry in which carbon and O₂ are the principal products, and that CO₂ can be electrolyzed inexpensively. Thermochemical and experimental results indicate that the principal carbon-deposition reaction in molten Li₂CO₃ or Li₂O/Li₂CO₃ electrolytes at 750 掳C is Li₂O + 2CO₂ 鈫?Li₂CO₃ + C + O₂. The reaction occurs at high Faradaic efficiency of the 4e^{鈥?/sup> reduction of CO₂ to carbon and oxygen at an electrolysis voltage as low as <1 V. Electrolytes without lithium carbonate but containing calcium and/or barium carbonate can also be employed as reaction media for successful carbon deposition, e.g. in an Na/BaCO₃ melt. However, the electrolysis reduction in pure Na or K or Na/K carbonate eutectics at 1 atm of CO₂ forms metals and/or gases, i.e., CO.}