Hydrogen penetration rates of iron. Effect of halide ions, hydrogen sulfide and hexynol

The effect of the halides (Cl − , Br − and I − ) on the rates of the hydrogen evolution reaction (h. E. R.) and hydrogen penetration (h. P.) of iron in H 2 SO 4 is determined. The H. E. R. and H. P. of Fe in these same electrolytes with the addition of H 2 S are also studied. The inhibition of corrosion and h. p. in the H 2 S environment by hexynol are compared. With halide addition her., i corr and h. p. decreased in the following order, Cl − > Br − > I − . H 2 S catalyzed both the h. e. r. and h. p. The catalytic activity does not appear dependent on the H 2 S concentration for the H. E. R. but does for H. P. The fraction of hydrogen generated which is absorbed by Fe is greater during corrosion when a new surface is formed continuously than during cathodic polarization. The addition of the acetylenic alcohol, hexynol, in H 2 SO 4 containing H 2 S and halides inhibited the h. e. r. corrosion and h. p.