Transfer function analysis of hydrogen permeation through a metallic membrane in a Devanathan cell. I. Theory

Various transfer functions were calculated for hydrogen permeation through a metallic membrane in a Devanathan cell. Surface processes such as hydrogen adsorption and evolution were taken into account in addition to the hydrogen penetration process and its diffusion through the bulk metal. The main transfer functions are the input impedance ΔV1/ΔI1 and the permeation transfer function ΔI2/ΔI1 between the output current and the input current from which the transconductance transfer function ΔI2/ΔV1 can be calculated. These quantities were obtained for potentiostatic controls of the input and/or the output sides. The effect of the changes of some characteristic kinetic parameters on these transfer functions were analyzed and their simplified expressions were derived for a few limiting cases. This gives a tool to interpret experimental data in a large set of conditions.