Green Hydrogen Production by Anion Exchange Membrane Water Electrolysis: Status and Future Perspectives

Green hydrogen production, i.e., produced on a CO2-neutral basis through the electrolysis of water employing renewable electricity, has attracted increasing attention. The electricity required is generated from Renewable Energy Sources (RES), for example, wind energy, hydropower, or solar energy. Since neither the process of production nor the end products of H-2 and O-2 are harmful to the environment, green hydrogen is climate neutral. Developing electrolysis technology is, therefore, a research topic to follow. Anion Exchange Membrane (AEM) Water Electrolysis (WE) is an innovative technology that couples the advantages of the more mature technologies of Proton Exchange Membrane (PEM) and conventional alkaline electrolysis, with the potential to eliminate the drawbacks of both. AEMWE technology is in an evolutionary stage and involves more investigation on several research topics, such as membrane and catalyst development and stability, as well as alternative feeding solutions that do not compromise the availability of fresh water. These topics are addressed in this paper, mentioning the state-of-the-art materials, new promising ones, and providing future research directions to improve AEMWE towards a most mature technology.