Nickel-Cobalt Alloys Electrodeposited at Controlled pH for Hydrogen Production in Alkaline Media

Simposio; 8th Symposium on Hydrogen, Fuel Cells and Advanced Batteries; 2022

HYCELTEC 2022

Nickel-Cobalt Alloys Electrodeposited at Controlled pH for Hydrogen Production in Alkaline Media.M. J. Gómez, G.I. Lacconi, E.A. FranceschiniINFIQC-CONICET, Dto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina. Pres. author: melisa.julieta.gomez@gmail.com1. IntroductionHydrogen has become an energy vector of interest, be-cause it allows the storage of energy from different sources, particularly interesting when is coupled with renewable ones. The combustion of hydrogen generates only water, thus avoiding the emission of polluting gases that promote global warming. Hydrogen can be produced through the electrolysis of water, usually carried out in alkaline liquid electrolyzers (AEL), using nickel electrodes as catalysts for the hydrogen evolution reaction (HER). It is known that the formation of alloys with other transition metals, such as co-balt, generates a significant increase in the activity of the HER catalysts. The formation of alloys alters the position of the nickel "d" bands, and with them, its Fermi level. These new alloyed materials can be obtained as an electrochemi-cal deposition coating by simply adding the precursor salts to the traditional Watts bath.NiCo alloys possess distinctive mechanical, thermophys-ical and magnetic properties; and compared to pure nickel, NiCo deposits have higher hardness and better wear and corrosion resistance. Several publications evaluated their catalytic activity for HER in alkaline media, working with al-loy coatings with different Ni/Co ratios [1]?[3]. All of them conclude that the HER at NiCo electrodes is superior to that of Ni. However, the correlation between the catalytic activi-ties of the alloys and the structural properties is not exhaust-ively carried out. In a previus work [4], we study the NiCo alloy in electrochemical baths with different Co2+ proportion and pH. Now we present a morfollogical and electrochemi-cal study, using a modified nickel Watts bath, with a con-trolled pH.