Hydrogen evolution reaction (h.e.r.) in an acidic or basic medium on nickel electrodeposited with PW₁₂O ^3-₄₀ and Cu²⁺

Abstract

The hydrogen evolution reaction (h.e.r.) on electrodeposited nickel from a chemical bath containing Cu^2-, with and without PW₁₂O ^3-₄₀ , was investigated. Hydrogen cathodes based on nickel-copper alloys and PW₁₂O ^su3-₄₀ reduced species are better electrocatalysts in 1 M H₂SO₄ or 3m KOH at 298 K than nickel-copper alloys deposited without PW₁₂O ^3-₄₀ . The electrocatalytic performance of the former cathodes was attributed to their chemical composition. This electrocatalytic activity for the h.e.r. was examined as a function of the [Cu²⁺] or [PW₁₂O ^3-₄₀ ] in the electrodeposition bath. The influence of nickel salt anions on the h.e.r. electrocatalytic activity of the electrodes was also investigated. The chemical surface composition of the electrodes was analysed by X-ray photoelectron spectroscopy (XPS). It was shown that the electrocatalytic parameters were correlated to the quantity of tungsten in the electrode surface. The various factors causing the improvement in the electrocatalytic activity are discussed.