Involving Surface Blockage by Adsorbed Hydrogen

Mechanisms Involving Surface Blockage by Adsorbed Hydrogen 

The coexistence of hydrogen evolution with iron dissolution at the corrosion potential justifies an exhaustive analysis of the influence of coverage of the metal by atomic and molecular hydrogen on the kinetic behavior of the iron electrode. 

This analysis showed that the above mechanism cannot account for higher dependences on the pH such as = -60 mV and 

The next iterative analysis of the influence of adsorbed hydrogen on the iron dissolution kinetics included the possible correlation between the surface structure and the reactions occurring at specific sites, as revealed by experimental and theoretical studies by Allgaier and Heusler, Lorenz and co-workers, and Keddam andco-workers. All these authors agreed that the dissolution rate constant should be proportional to the weakness of the binding of the surface atoms to the bulk metal, thus decreasing in the order kink step plane. The rate of metal dissolution is proportional to the rate constant and to the number of atoms in the position concerned, which decreases in the order plane step kink. 

2FepHad FepH2ad + Fep FepH2ad Fep + H2soi FeFek % Feld + + Fek 

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