In the search for a good DSA-type O2-evolving electrode, the influence of the base metal (titanium, tantalum, zirconium, niobium and some of their alloys) on the performance of IrO2-Ta2O5 coated electrodes, was investigated. The thermal behavior and oxygen affinity sequence of the metals, in relation to the electrode prepn. procedure, were detd. thermogravimetrically. The chem. and electrochem. stability of the base metal was found to be directly related, through the wear mechanism, to the service life of the electrode, measured in 30% H2SO4 at 80 Deg and 750 mA cm-2. Tantalum-based electrodes were shown to have the highest service life; 1700 h, compared with the 120 h for titanium-based electrodes. [on SciFinder (R)]