A New Anion Exchange Membranes Pretreatment Protocol for Hydrogen Production by Water Electrolysis

Abstract

This study examines the impact of pretreatment techniques on anion exchange membrane (AEM) used in water electrolysis for hydrogen production. A new pretreatment protocol is proposed, involving membrane immersion in Milli-Q water for 7 days and 8 h conditioning in the electrolytic stack. The new pretreatment protocol is compared with three conventional protocols, based on short-term exposure to alkaline electrolytes (0.1M KOH). Morphological analysis using scanning electron microscopy-energy-dispersive X-ray detector and electrochemical performance evaluation through polarization curves are conducted. Results show that the new pretreatment protocol improves hydrogen production efficiency by 2.6% compared to conventional alkaline pretreatments. This improvement is resulting of an increase in membrane hydration during the pretreatment, which benefits the ion-exchange process during the 8 h conditioning, reducing chlorine ion content from 0.2% to 0.1%. Tafel slope analysis further supports these findings. These study highlights the need for further research on AEM pretreatment protocols to optimise hydrogen production by electrolysis performance, reduce the use of reagents and mitigate the effects of long-term degradation of membranes.