Development of High-Performance High Entropy Alloy Electrocatalysts for Hydrogen Production Using Cold and Warm Spray Processes

Hydrogen production through water electrolysis is a well-established process. However, its large-scale economic viability remains a challenge due to high energy consumption as well as material costs and limited durability of the electrodes in harsh electrolytic environments. In this context, there is a need for the development of cost-effective electrode materials that can withstand severe operating conditions while maintaining high performance. High entropy alloys (HEAs) are promising electrode material candidates due to their unique elemental combinations, offering synergic effects that enhance electrocatalytic activity, chemical stability and structural integrity. In this study, cold and warm spray solid-state deposition technologies were used for the fabrication of FeCoNiCrMn, FeCoNiCrMo and FeCoNiCrTi HEA electrocatalysts in a single step process. Both processes are scalable and commercially viable solid-state manufacturing techniques that allow for rapid and cost-effective production of electrodes, preserving the critical properties of HEAs that is necessary for their optimal performance. The resulting coatings were characterized by their microstructures, surface roughness, electroactive surface areas and electrocatalytic activities. Correlations between spray parameters, electrode’s composition, coating characteristics and their electrocatalytic performance is established and will be discussed in relation to the specific attributes of each spray process.