Electrocatalytic behavior of Ni-based amorphous alloys for hydrogen evolution

Ni-based amorphous alloys were synthesized by rapid quenching from the melt, using a planar flow technique. Their amorphous nature and thermal stability were studied by X-ray diffraction and differential scanning calorimetry. The electrocatalytic activity of the as-quenched amorphous alloys with respect to the hydrogen evolution reaction (HER) in alkaline water electrolysis was studied in relation to the alloy composition. The kinetic parameters of the HER were evaluated by cyclic voltammetry and impedance spectroscopy techniques in 6 M KOH at room temperature. The electrocatalytic activity of the amorphous alloys was found to depend on the alloy composition. It was obtained that molybdenum containing amorphous alloys (Ni–Mo–B) showed a superior electrocatalytic activity in the HER compared to Ni–(Nb,Ta)–B and Ni–Si–B, as Ni66.5Mo28.5B5 revealed considerably lower charge transfer resistance and higher exchange current density than Ni63Mo27B10. The results have to be attributed to an improved intrinsic activity of the Ni–Mo–B alloys compared to the other Ni-based glasses.