The corrosion of iron in electrolytic dimethylformamide solutions of some carboxylic acids and the effect of added halide ions

Abstract

Polarization studies were carried out on the corrosion of iron in electrolytic N,N-dimethylformamide (DMF) solutions of carboxylic acids. The cathodic, proton reduction was mainly associated with the concentration of proton solvated with contaminant water in the DMF solutions. Since the rate of anodic, iron dissolution was related to the concentration of the contaminant, it is proposed that there is an OH − catalysed process of anodic dissolution in the DMF solutions of carboxylic acid. By the addition of halide ions Cl −, Br − and I − to the DMF solutions, the anodic process of iron corrosion was stimulated, differing from that in aqueous and methanol solutions. The cathodic and anodic processes were discussed on the basis of the donor and acceptor numbers of DMF.