Effect of adsorbed hydrogen on the iron dissolution rate: A study by the cyclic stepwise variation of potential

It is shown that the iron dissolution rate in acid sulfate electrolytes may drop following an increase in the frequency of a cyclic stepwise variation of the potential. The results, obtained at different amplitudes and mark-t o-space ratios of cyclic potential pulses, confirm that this effect is conn ected with an increase in the iron surface coverage by hydrogen atoms. Rate constants are determined for reactions of discharge of hydrogen ions, chem ical recombination of hydrogen atoms, and hydrogen exchange between the sur face and metal phase. The coverage of the surface of iron is calculated in potentiostatic conditions and when cycling a potential step. As a result, a connection is found between the amount of adsorbed hydrogen and the iron d issolution rate at a constant potential.