Cathode for electrolysis of aqueous solution of alkali metal halide
AssigneeShowa Denko K.K.
InventorsKeiji Kawasaki, Itsuaki Matsuda
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Abstract
An improved cathode for the electrolysis of an aqueous solution of an alkali metal halide, which shows a reduced hydrogen overvoltage. The cathode comprises a metallic substrate and a coating of iron or both iron and cobalt electroplated thereon from a specified electroplating bath containing iron or both iron and cobalt. A method is also provided for electrolyzing an aqueous solution of an alkali metal halide using this cathode.
Claims12
A cathode for electrolysis of an aqueous solution of an alkali metal halide, said cathode being composed of a metallic substrate and a coating of iron metal or iron metal and cobalt metal deposited on its surface at a current density of 1 to 10 A/dm.sup.2 and a temperature of 20.degree. to 90.degree. C. from an aqueous electroplating bath consisting essentially of an aqueous solution having a pH value of from 2.5 to 6.0 containing therein
- (i) a metallic ion of Fe.sup.++ or Fe.sup.++ together with Co.sup.++ in an amount of 0.5 to 0.9 moles/liter, and
- (ii) an additive selected from the group consisting of dextrin, water-soluble starch, poly(2-diethylaminoethyl methacrylate) and poly-aluminum chloride, said additive being employed at a concentration of 0.5 to 10 g/liter and said bath being free from an ammonium ion.
In the process for electrolysis of an aqueous solution of an alkali metal halide, the improvement which comprises using a cathode for the electrolysis of an aqueous solution of an alkali metal halide, said cathode being composed of a metallic substrate and a coating of iron metal or iron metal and cobalt metal deposited on its surface at a current density of 1 to 10 A/dm.sup.2 and at a temperature of 20.degree. to 90.degree. C. from an aqueous electroplating bath consisting essentially of an aqueous solution having a pH value of from 2.5 to 6.0 containing therein
- (i) a metallic ion of Fe.sup.++ or Fe.sup.++ together with Co.sup.++ in an amount of 0.5 to 0.9 mole/liter, and
- (ii) an additive selected from the group consisting of dextrin, water-soluble starch, poly(2-diethylaminoethyl methacrylate) and poly-aluminum chloride, said additive being employed at a concentration of 0.5 to 10 g/liter and said bath being free from an ammonium ion.
Dependencies are inferred from the claim text.