Experimental and DFT study of CoCuMo ternary ionic activator for alkaline HER on Ni cathode

Abstract In this work, nickel (Ni) cathode for hydrogen evolution reaction (HER) in alkaline medium, was modified by a combination of in situ ionic activators, based on three d-metals (Co, Cu and Mo). Catalytic performance of new Co-Cu-Mo cathode was improved compared to pure Ni in view of both increased HER reaction rate and improved energy efficiency - reduction of energy consumption of a model electrolytic cell by 15%. We discussed obtained results in comparison with previously investigated similar systems (Ni-Co-Mo and Ni-Cu-Mo). In addition, we perform a detailed surface characterization by a series of experimental techniques (XRF, XRD, SEM, profilometry and EIS) and employ DFT calculations to provide a more detailed discussion of the origin of obtained catalytic performance.