Electrodeposition of Ni-transition alloys for the oxygen evolution reaction

The oxygen evolution reaction (OER) is the anodic reaction in several industrial electrolytic processes. The objective of this work was to develop a new electrocatalytic material for long-lasting and economical high performance electrodes. New electrodes were prepared by electrodeposition of nickel, nickel-ruthenium and nickel-iridium alloys. They were then activated by anodic polarization at 100 mA cm^–2 to form an oxide layer. The electrocatalytic activity was characterized for the OER in 5M KOH solution. The results show that nickel-iridium alloys provide greater electrocatalytic activity for the OER and better corrosion resistance than nickel-ruthenium in alkaline solution. The effects of transition elements on improving the performance of the nickel electrode are then discussed.Notation b Tafel slope - i _ex exchange current density - i _dp electrodeposition current density - i _OER oxygen evolution reaction current density - C _dl double-layer capacity - o₂ oxygen overpotential