Exploring the potential of ammonia electrolysis for hydrogen production: from lab-performance to stack architectures

Hydrogen production via ammonia electrolysis is a promising alternative but still faces significant challenges hindering its practical deployment. Research has primarily focused on the development of anodic electrocatalysts, while limited studies address their integration into a functional laboratory-scale electrolyzer. Indeed, only two notable large-scale investigations have been reported. This review provides insight into the advances achieved in the past five years in the field of ammonia electrolysis, encompassing both small- and large-scale systems. First, the ongoing trends in the design of noble and non-noble electrocatalysts to maximize activity and stability have been analyzed. At the laboratory scale, the influence of crucial elements (porous transport layers and membranes) as well as the operational parameters (such as feed composition, temperature, etc.) is discussed, highlighting the most promising approaches to improve overall electrolyzer performance. At a larger scale, the main achievements are associated with system scale-up, particularly those related to stack design and material availability. • Scalable ammonia electrolysis is boosted by zero-gap cells. • Zirfon separators prove enhanced resistance to alkaline and NH 3 -rich conditions. • Ammonia electrolysis is demonstrated in stacked pilot systems (3000 cm −2 six-cell). • Large-scale implementation is limited by the cell component materials supply.