Ni and NixCoy Alloys Electrodeposited on Stainless Steel AISI 316L for Hydrogen Evolution Reaction

MELISA J. GOMEZ; ESTEBAN A. FRANCESCHINI; GABRIELA I. LACCONI

Electroactalysis

Springer

Año: 2018

1868-2529

NixCoy electrocatalysts for hydrogen evolution reaction (HER) were synthesized by electrodeposition on AISI 316L stainless13 steel (denoted as SS316L), as a scalable and economical alternative to be used in alkaline electrolyzers. For this, a previous14 treatment of the SS316L surface was carried out in order to optimize the deposition of different catalytic films containing Ni and15 NixCoy with different compositions (Ni89Co11, Ni69Co31, and Ni29Co71). The properties of the catalysts were established by16 scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD), and the17 catalytic activity for HER was evaluated by potentiodynamic experiments in 1 M KOH solutions. An increase in the current18 density toward the hydrogen evolution reaction was found with these NixCoy electrodes. For the Ni69Co31 catalyst, current19 density values 112% higher than those recorded with deposited Ni from conventional Watts bath were obtained. The HER20 current shows a strong dependence on the content of Co on the alloy that is also evidenced in the electrochemical impedance21 experiments. The efficiency of electrocatalytic activity for HER was increased after an electrochemical aging treatment, indicat-22 ing the presence of an activation process, for example with Ni89Co11 electrodes, where higher current density for HER was23 observed.