The difference between gas-generating porous hydrophilic electrodes (G
PHE) and similar systems employed in fuel cells (FC) is that, at appro
ximate equality of current densities, the thicknesses of FC (expressed
in millimeters) are an order of magnitude larger than those of GPHE.
The estimations and calculations performed in this paper explain this
difference. Good agreement between the experimental and theoretical da
ta related to GPHE is obtained.