An electrode having a lead base and a catalyst is manufactured by (a) compressing titanium sponge particles so as to consolidate them to a coherent porous layer, (b) applying the catalyst to the titanium sponge particles, and (c) fixing the layer of consolidated sponge particles to the lead base. The catalyst is formed on the titanium sponge particles before or after their consolidation to a coherent layer. This layer may be produced and fixed to the base in a single compressing and fixing step combining (a) and (c). Oxygen is anodically evolved at a reduced, stable potential by means of this electrode, so that it can be usefully applied as an anode in processes for electrowinning metals from acid electrolytes.