Abstract

Multiprincipal element alloys of the system Fe50-xMn30Cr10Co10Bx (x = 0, 3, 5, 10 at.-%) are evaluated as electrocatalysts for hydrogen generation. Alloys were produced from pure elements via Spark Plasma Sintering, in quenched and thermal treated states (MPEAs-Q-Bx and MPEAs-TT-Bx). Catalytic evaluation was carried out in acidic and basic medium. The microstructure is predominantly FCC in the matrix, accompanied by BCC, HCP (epsilon-martensite), and tetragonal M2B boride phases. The alloys evaluated exhibit performances in the range of reported non-precious metal electrocatalysts, both in HER and OER reactions, being the basic media more stable. In HER the best performance is shown in the system MPEAs-Q-B0 exhibiting an overpotential of-417 mV, associated to the structure of the solid solution. In OER the MPEAs-TT-B0 shows 430 mV at 10 mA/cm2 attributed to oxidized species formation. The alloys evaluated in this work are good candidates to be implemented in electrochemical water splitting for green hydrogen production facilities.