The kinetic study of the electrocatalytic hydrogen evolution reaction (HER) in the presence of the -oximehydrazonate iron(II) bis-clathrochelates in different media (including aqueous solutions) withvarious H-acids as the source of H+ions showed that the rate-limiting stage of such electrocatalytic2H+/H2 reaction is the protonation of two encapsulated electrochemically generated iron(I) metallocen-ters and the general kinetic scheme of this process persists irrespective of a source of H+ions.