Preparation of Lanthanum Nickel Oxide-Coated Ni Sheet Anodes and Their Application to Electrolytic Production of (CF_3)_3N in (CH_3)_4NF cercent dot 4.0HF Melt

摘要

A new process for electrolytic production of a perfluorinated compound, (CF_3)_3N, using lanthanum nickel oxide-coated Ni sheet anode in the (CH_3)_4NF center dot 4.0HF melt at room temperature, was developed. Thin films of the lanthanum nickel oxides were prepared on Ni sheets by sol-gel coating method using polyvinlylpyrrolidone (PVP). The main components of the thin films were La_2O_3, LaNiO_3, and La_2NiO_4 at 500, 750 and 1000 deg C , respectively. The anode performance in the (CH_3)_4NF center dot 4.0HF melt depends greatly on the main component of the thin film, and the LaNiO_3-coated Ni sheet anode gives the best anode performance. The potential of LaNiO_3-coated Ni sheet anode remains constant at 5.9 V during electrolysis at 20 mA center dot cm~(-2) in the (CH_3)_4NF center dot 4.0HF melt for 100 h. This is because LaNiO_3 and NiF_3 and/or Ni_2F_5, the latter of which was formed during electrolysis, in the film give a high electronic conductivity to the surface film during electrolysis. The maximum mole fraction of (CF_3)_3N (21.4 percent) was obtained at 20 mA center dot cm~(-2) in (CH_3)_4NF center dot 4.0 HF melt using the LaNiO_3-coated Ni sheet