The Effect of Chromium Particles on Nickel Electrodeposition

Abstract

In order to obtain an understanding of the mechanism of chromium particle occlusion in electrodeposited stainless‐steel‐type coatings, the U.S. Bureau of Mines has studied the effect of chromium particles on nickel electrodeposition. The chromium particles catalyzed nickel electrodeposition on a vitreous carbon surface. Chromium particle additions, when added to Watt's‐type electrolytes, of , shifted the nickel reduction wave to more positive potentials on a vitreous carbon surface. From rotating cylinder electrode studies it was concluded that nickel deposition with or without chromium particles is a kinetically limited rather than mass‐transfer‐limited process. Electrochemical impedance spectroscopy experiments with and without chromium particles verified the rate‐determining step proposed by Epelboin, with the Ni+(ads) limiting the nickel electrodeposition. The chromium particles appear to enhance the formation of this intermediate.