Correlation of microstructure and catalytic activity of crystalline Ni–Co–Y alloy electrode for the hydrogen evolution reaction in alkaline solution

The electrocatalytic activity of crystalline Ni65Co29Y6 alloy with respect to the hydrogen evolution reaction (HER) was studied in relation to its microstructure examined by optical microscopy, scanning electron microscopy coupled with electron probe microanalysis, and XRD measurements. Kinetic parameters of the HER were evaluated on the basis of electrochemical impedance spectroscopy and steady-state polarization techniques in 1 M NaOH solution at room temperature. The results were compared with those obtained on polycrystalline Ni metal. The enhanced electrocatalytic activity observed for the HER on the investigated alloy was ascribed to a pronounced synergetic effect between the alloy constituents, i.e. Ni63Co37 and (Ni,Co)17Y2 intermetallic compounds.