On the use of WO<inf>4</inf>²⁻ as a third component to Co–Mo ionic activator for HER in alkaline water electrolysis

Abstract

This study investigates the impact of Co–Mo–W ionic activators on the hydrogen evolution reaction (HER) in alkaline electrolysis, comparing their performance to Co–Mo and Co–W systems. The research focuses on analyzing the catalytic efficiency of these activators under varying conditions, including temperature and current density variations. Key findings reveal that the Co–Mo–W activator enhances HER performance, with a significant 17% reduction in energy consumption compared to plain electrolyte, mirroring the efficiency of Co–Mo. Tafel analysis gave the insight of the reaction mechanism for HER for all activators, with Co–Mo–W exhibiting a lower Tafel slope, suggesting improved catalytic activity. Structural and morphological analysis of electrode coatings shows a highly developed surface for Co–Mo–W, with a roughness factor similar to or slightly lower than the most developed Co–Mo coating. The study concludes that the synergistic combination of Co, Mo, and W in a tri-component ionic activator offers a promising catalytic activity for HER, outperforming bi-component systems and presenting significant potential for industrial-scale alkaline water electrolysis applications.