A preliminary study was made of the cathodic properties (redn. of Ce(IV) and hydrogen evolution) of ZrO2 layer formed on Zr by thermal decompn. at high temp. Zr was chosen as base metal due to the fact that this valve metal is stable under conditions of hydrogen evolution. The Zr/ZrO2 cathode has a higher hydrogen evolution overpotential than Zr and the overpotential for Ce(IV) redn. is strongly increased at the Zr/ZrO2 cathode. [on SciFinder (R)]