Method of electrolytically synthesizing nitrogen trifluoride

Abstract

The present invention provides an electrolytic synthesis method of nitrogen trifluoride, comprising electrolytically synthesizing nitrogen trifluoride gas from ammonium fluoride in an ammonium fluoride-containing molten salt mixture using a carbonaceous electrode as an anode, wherein the method comprises: a step of dissolving, in the molten salt mixture, metal ions capable of electrolytically yielding a highly oxidized metal fluoride through reaction with fluorine radicals (F.) that are generated upon the discharge of fluoride ions which are a component of the ammonium fluoride, thereby reacting the metal ions with the fluorine radicals (F.) to yield the highly oxidized metal fluoride, and reacting the highly oxidized metal fluoride with ammonium ions on a surface of the electrode and in a solution to synthesize nitrogen trifluoride gas.

1 . An electrolytic synthesis method of nitrogen trifluoride, comprising electrolytically synthesizing nitrogen trifluoride gas from ammonium fluoride in an ammonium fluoride-containing molten salt mixture using a carbonaceous electrode as an anode, wherein the method comprises:
 a step of dissolving, in the molten salt mixture, metal ions capable of electrolytically yielding a highly oxidized metal fluoride through reaction with fluorine radicals (F.) that are generated upon the discharge of fluoride ions which are a component of the ammonium fluoride,   thereby reacting the metal ions with the fluorine radicals (F.) to yield the highly oxidized metal fluoride, and reacting the highly oxidized metal fluoride with ammonium ions on a surface of the electrode and in a solution to synthesize nitrogen trifluoride gas.   
   
   
       2 . The electrolytic synthesis method of nitrogen trifluoride according to  claim 1 , wherein the carbonaceous electrode is one selected from an amorphous-carbon electrode, a graphite electrode, a carbon electrode containing a metal fluoride, and a conductive-diamond electrode. 
   
   
       3 . The electrolytic synthesis method of nitrogen trifluoride according to  claim 1 , wherein the carbonaceous electrode comprises a base which is made of graphite or amorphous carbon. 
   
   
       4 . The electrolytic synthesis method of nitrogen trifluoride according to  claim 1 , wherein the molten salt mixture comprises NH 4 F—KF—HF or NH 4 F—HF. 
   
   
       5 . The electrolytic synthesis method of nitrogen trifluoride according to  claim 1 , wherein the metal ions comprise ions of at least one metal selected from the group consisting of Ni, Mn, Co, Li, and Cs, and the concentration of the metal ions in the electrolyte is desirably from 0.01 M to a saturation concentration. 
   
   
       6 . The electrolytic synthesis method of nitrogen trifluoride according to  claim 1 , wherein the anode has a current density of 0.01-10 A/cm 2  at the time of the electrolysis.