The hydrogen evolution reaction on amorphous Pd-Si alloys

Abstract Amorphous metallic alloys with compositions Pd 80 Si 20 , Pd 82 Si 18 , Pd 85 Si 15 and Pd 79 Au 4 Si 17 were prepared by the roller quenching method. The morphology and composition of the alloys were determined by X-ray, scanning electron microscopy and energy-dispersive X-ray techniques. In order to characterize their electrochemical behavior they were used as cathodes for the hydrogen evolution reaction in 0.5 M KOH solutions at room temperature. The mechanism of this reaction, the rate constants of the different steps and the characteristics of adsorption of intermediates on the different amorphous alloys were determined by impedance techniques. The reaction follows a Volmer-Tafel mechanism with the Tafel reaction being the rds.