ar 5h 2 flow rate between 65 and 145 cm 3 min u2212 1 at higher gas flow for every current density the cell voltage drastically increases this is attributed to the high gas flow rate which in the case of a homogeneous distribution of small bubbles on the overall surface of the electrode must generate a resistive layer this is of great interest because it indicates that the flow rates used until now are too high and are not appropriated for a gas diffusion anode however low flow rates with a gas mixture containing only 5 at h 2 do not provide enough hydrogen for the electrolysis reaction which can also explain the small voltage reduction observed previously ideally pure hydrogen has to be used in order to obtain a significant cell voltage reduction porous graphite represents the most promising type of hydrogen anodes for magnesium electrolysis tested no noticeable trace of corrosion were found on the carbon anodes thus it appears that carbon represents an ideal choice of anode material for magnesium electrolysis because of its excellent corrosion resistance at high temperature in mgcl 2 based molten salt in addition it was observed that hydrogen was capable of diffusing through the electrode.