Electrocatalytic Activity of Amorphous Ni-Nb-Y Alloys for the HER in Alkaline Water Electrolysis

摘要

The recent development of anion exchange membranes (AEM) has renewed interest in alkaline water electrolysis for large-scale production of hydrogen gas. New electrocatalysts are required to interface with such AEMs in advanced alkaline water electrolyser designs. The present work assesses the role of structure and chemistry on the catalytic activity of cryomilled Ni-Nb-Y amorphous alloys towards the hydrogen evolution reaction. X-ray diffraction and TEM studies characterized the microstructure of the Ni-Nb-Y catalysts. Kinetic data from potentiostatic polarization and EIS measurements support the hypothesis of enhanced activity resulting from the multiphase catalyst structure. The novel multiphase Ni_(81.3)Nb_(6.3)Y_(12.5) catalyst displayed the greatest catalytic activity. This improvement is attributed to the presence of a crystalline Ni_5Y secondary phase finely dispersed in the yttrium-rich Ni-Nb-Y amorphous matrix. The results herein demonstrate that mechanically alloyed Ni-based amorphous-based materials are promising catalysts for electrochemical hydrogen production.