Large specific surface area nanocrystalline Ti-Ru-Fe cathode materials forsodium chlorate

Ball-milled nanocrystalline Ti3RuFe powders were mixed with 1, 2, 4, 10 and 20 equivalents of Al and the mixtures were milled again for 20 h. The amou nt of Al atoms dissolved into the B2 structure of Ti3RuFe does not exceed 8 -9 at %, the remaining being present as elemental Al into the powder mixtur e. During a subsequent treatment of the composite powder in alkaline soluti ons, the elemental Al is leached out, while Al solutes in the B2 structure are not affected. An examination of the surface by scanning electron micros copy reveals that the leached powder has a highly porous surface structure. Surface area measurements performed by BET measurements show that there is a tenfold increase in the effective surface area. Activated electrodes mad e from these porous materials show a significant decrease of the cathodic o verpotential for hydrogen evolution in typical chlorate electrolysis condit ions of about 80 mV.