CATHODIC BEHAVIOR OF AMORPHOUS NI0.33ZR0.67 ALLOY IN 30 W/O KOH AT 70-DEGREES-C

The electrocatalytical properties for hydrogen evolution on amorphous Ni//0//. //3//3Zr//0//. //6//7 alloy were investigated in 30 w/o KOH at 70 degree C. This material produces its best performance after an appropriate chemical activation in 1 M HF. Surface and electrochemical analysis of the activation indicated that the electrode surface composition and activity are substantially modified only after 10 s in the acidic solution. The electrocatalytic activity was strongly reduced by cathodic polarization and the deactivation process was related to hydrogen absorption and, eventually, hydride formation at the electrode. The latter phenomenon leads to hydrogen embrittlement of the electrode.