C. Montella, EIS study of hydrogen insertion under restricted diffusion conditions - I.Two-step insertion reaction, J ELEC CHEM, 497(1-2), 2001, pp. 3-17
The theoretical expressions for the Faradaic impedance and electrode impeda
nce are derived for indirect (two-step) insertion of hydrogen in metals and
alloys, irrespective of the mass transport conditions in the electrode. Ne
xt, impermeable boundary (restricted diffusion) conditions are considered.
The determination of the hydrogen concentration, diffusion coefficient and
kinetic parameters from EIS data is discussed. The thermodynamic and kineti
c conditions for which it is possible to distinguish between the direct ton
e-step) insertion mechanism and the indirect (two-step) mechanism on the ba
sis of EIS data are analysed. Previous results in the electrochemical liter
ature are discussed in relation to the theoretical derivation in this paper
. (C) 2001 Elsevier Science B.V. All rights reserved.