| 摘要 |
Chloroacetic and bromoacetic acids are dehalogenated by electrolysis of aqueous solutions of these acids using carbon cathodes and anodes likewise of carbon or of other conventional electrode materials in undivided or in divided electrolysis cells; the aqueous electrolysis solutions in the undivided cells and in the cathode area of the divided cells contain, in dissolved form, one or more salts of metals having a hydrogen excess-voltage of at least 0.4 V (at a current density of 4,000 A/m2). Metals having a hydrogen excess-voltage of at least 0.4 V (at a current density of 4,000 A/m2) are, for example, Cu, Ag, Au, Zn, Cd, Hg, Sn, Pb, Ti, Zr, Bi, V, Ta, Cr and Ni. The process allows high current densities (up to about 8,000 A/m2) to be used without or virtually without corrosion of the electrodes and without deposit formation on the electrodes.
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