Investigation of the electrocatalytic behaviour of Fe–MM (MM = Mischmetal) crystalline alloys for hydrogen evolution reaction in alkaline medium

Fe–MM (MM = mischmetal) crystalline alloys have been characterized by means of microstructural and electrochemical techniques in view of their possible application as electrocatalytic materials for the hydrogen evolution reaction (HER). The microstructure of the alloys investigated (Fe95MM5, Fe85MM15, Fe80MM20, Fe70MM30) has been characterized by phase analysis techniques (SEM-EPMA, XRD). The electrocatalytic efficiency has been evaluated on the basis of electrochemical data obtained from cathodic polarization curves and ac impedance measurements carried out in 1 M NaOH solution at 298 K. The microstructural features play a fundamental role in determining the electrocatalytic activity of the investigated alloys. The overall experimental data indicate that interesting electrocatalytic performances are obtained with the Fe80MM20 electrode, which exhibits the highest activity towards the HER.