Patterned Electrodes for Hydrogen Production in Alkaline-Water Electrolysis

Over the last decade, there has been a re-emergence of hydrogen as a clean fuel for the energy transition towards net-zero carbon emissions. Hence, significant interest has been shown in low-carbon and green hydrogen to power this transition. Water electrolysis has been identified as the most common method for green hydrogen production. However, increasing cell faradaic efficiencies for deployment at scale involves improving every part of the system, e.g., the electrodes. Recent investigations have suggested that the surface structure of electrodes can affect hydrogen evolution by increasing the active surface area of reaction. Yet, this has been explored with micro-pillars and micro-pits which have complex manufacturing processes. Hence, this study investigates surface macro-pits and patterns as more suitable replacements for industrial application. Steady-state, multi-phase computational simulations were carried out to investigate the characteristics hydrogen evolution over flat and macro-dimpled electrodes. Two current densities in alkaline-water electrolysis were explored. The results show that macro-dimples significantly eliminate static gas pockets when compared to flat electrodes suggesting more dynamic bubble detachment. Furthermore, dimple size also affects the HER process. In summary, the results hint at macro-patterns being promising in controlling hydrogen bubble evolution for better electrolytic cell performance for green hydrogen production.