ELECTROREDUCTION MECHANISM FOR TRANSITION-METALS

The similarity of the structures and of the compositions of the intermediate reduction products of such transition metals as copper, manganese, chromium, nickel, rhenium, molybdenum, tungsten and zirconium indicates that their reduction from aqueous solution takes place by the same mechanism. The presence of low valency compounds in the solid phase indicates that they exist in the cathodic zone, i. e. in the material of the cathode film which is formed as a result of the accumulation of a sufficient amount of low valency compounds of the respective metals at a given polarization value, the cathode layer being alkalized at the same time. The formation of real bifunctional systems makes it possible to produce functional coatings and to electrocrystallize metals with deposition potentials that are more negative than with hydrogen.