The suitability of a selection of amorphous alloys as electrocatalysts or as inhibitors for hydrogen evolution (HE) was investigated in 1 M KOH at 25°C. Mild basic conditions were chosen so as to make direct comparison with other data, where available. The alloys studied were the known glassy alloys Fe 67 Co 18 B 14 Si 1 , Co 66 Fe 4 Si 16 B 12 Mo 2 , Fe 40 Ni 40 B 20 and Fe 40 Ni 40 P 14 B 6 and an entirely new glassy alloy Zr 73.22 Ti 19.71 Cu 1.24 Fe 5.83 . The electrochemical techniques of slow sweep anodic and cathodic polarisation were used, in conjunction with the surface analysis techniques of scanning electron microscopy (SEM) and X-ray analysis, to characterise the alloys and new data has been obtained for all alloys. The glassy alloys were tested in their as-polished state, as well as after surface activation, by ex situ chemical (acid etching) and in situ electrochemical (anodic oxidation in base) pre-treatment. The least corrosion resistant composition, Fe 67 Co 18 B 14 Si 1 , displayed the highest activity for HE in the as-polished state and only a minor improvement resulted from surface pre-treatment. Corrosion resistance was partly characterised by the degree to which the passive region increased and the passive region current decreased as a function of pre-treatment. The most corrosion resistant alloy, Zr 73.22 Ti 19.71 Cu 1.24 Fe 5.83 , displayed the poorest activity for HE in the as-polished state, but a significant improvement resulted from surface activation by in situ anodic oxidation in basic media. Surface activation by acid pre-treatment reduced the corrosion resistance of the Zr 73.22 Ti 19.71 Cu 1.24 Fe 5.83 alloy and was, therefore, a non-viable and destructive procedure. However, acid pre-treatment was effective in substantially activating the glassy Co 66 Fe 4 Si 16 B 12 Mo 2 and Fe 40 Ni 40 P 14 B 6 alloys towards HE and did not alter the corrosion properties of these compositions. A novel technique for mounting thin alloy specimens has been developed, using an insulating photo-resist coating, resulting in sharply defined electrode edges.

The influence of Mo, V, W in ferrochrome alloys and of SO4 , C104, Clin an aqueous electrolyte was investigated electrochemically. The effect of minor alloying elements was most pronounced in the active potential region, prior to passivation; Mo, V reduced pitting while W enhanced it. CIpromoted pitting whereas SO4 and CI04 were inhibitors. Removal of surface sulfate ions destroyed this inhibitive effect. Relationships were developed between Epjn Em,,, i,P and [anion] which enabled the prediction of [S0] and (CI -J required to inhibit and induce pitting respectively.

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