Amorphous alloy electrodes for anodic oxidation of sulfite

Amorphous Ni-valve metal alloys containing a few atomic per cent of platinum group elements were prepared by rapid quenching and were employed for electrochemical oxidation of sulfite in 0.075 M Na₂B₄O₇ + 0.3 M H₃BO₃ + 1 M Na₂SO₃ at 30°C. Of the amorphous alloy electrodes containing ruthenium, rhodium, iridium or platinum, the platinum-containing electrodes showed the highest activity, which was almost the same as or even higher than that of the platinized platinum black electrode. Furthermore, the combined addition of platinum and ruthenium enhanced the catalytic activity. When ruthenium was substituted for part of the platinum, the maximum activity for amorphous Ni40NbxPt(1 - x)Ru alloys was observed at about 0.8 at.% Pt.