The versatile properties of aluminum have established its extensive commercial and industrial roles. Aluminum forms a protective oxide layer when oxygen is present. Removing this oxide layer is the rate-determining step for aluminum corrosion, and soluble chloride is known to accelerate corrosion. The Cu(II) – Al redox reaction can be used as a model for studying the kinetics of aluminum corrosion. Halide acceleration of this reaction has been studied (Wei, Lee Chen 1994, Sobel and Cohen, 2010); halides do accelerate the Cu-Al redox displacement reaction. In this study aqueous copper(II) chloride was reacted with household aluminum foil at constant temperature. Hayes et al. (1989) studied the growth of silver halide clusters prior to formation of precipitate, and showed that silver ions can sequester halide without precipitate formation. To observe the effects of silver(I) on the reaction rate, 0.10 M copper(II) sulfate was reacted with aluminum foil in 0.001 M silver(I) nitrate with varied chloride ion concentrations. Small amounts of silver(I) reversed halide acceleration of the Cu(II)-Al reaction. In the absence of chloride ion, the reaction was completely inhibited by Ag(I). The data suggests that sulfate anion is not a neutral actor, but rather has a positive effect on the reaction.

Quantitative determination of silver inhibition of halide accelerated aluminum corrosion

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.