Electrochemical reduction of dichlorodifluoromethane in acetonitrile medium to useful fluorinated compounds

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• 作者：A. Schizodimou ; G. Kyriacou ; ^{kyriakou@vergina.eng.auth.gr} ; Ch. Lambrou
• 关键词：CFC-12 ; Dichlorodifluoromethane ; Electrochemical ; Reduction ; Difluoromethane ; Tetrafluoroethylene
• 刊名：Journal of Electroanalytical Chemistry
• 出版年：1999
• 出版时间：2 September 1999
• 年：1999
• 卷：471
• 期：1
• 页码：26-31
• 全文大小：123 K

文摘

The electrochemical reduction of dichlorodifluoromethane (CFC-12) at Ag, Cu, Au, Pt and Ni electrodes in acetonitrile and 0.1 M (C₄H₉)₄NBr as supporting electrolyte has been studied. The main gaseous products were found to be CF₂¤_CF₂, CH₂F₂ and CH₃F. Small amounts of CHClF₂ and CH₄ were also detected. Among the main products, CF₂¤_CF₂ and CH₂F₂ are of great practical importance, because the first is the monomer for the production of Teflon and the second is an excellent candidate for low temperature refrigeration applications, which in addition does not cause depletion of ozone. Silver was found to be the most efficient electrode for the reduction of CFC-12, because the rate of the reduction was greater than at the other metals and the current efficiencies for CF₂¤_CF₂ (38 % ) and CH₂F₂ (44 % ) were also high. Among the other electrodes, Pt gave also high current efficiencies but the reduction rate was much lower. The increase of the negative potential at the Ag electrode leads to a significant increase in the rate of the electrochemical reduction. The electroreduction of CFC-12 was also studied in mixed acetonitrile+water solutions. The experimental results indicated an almost linear decrease of the reduction rate with the increase of the water content. This was attributed to the decreased solubility of CFC-12 in water. The formation rate of CF₂¤_CF₂ was also significantly decreased.