Progress and prospects in direct ammonia solid oxide fuel cells

Hydrogen has emerged as a major energy vector in the past few years; however, its storage and long-distance transportation remain the key challenges to its widespread use. Ammonia is considered to be a potential medium for hydrogen carrier and storage. Indeed, ammonia is more energy dense than hydrogen, easier to transport, and allows for a CO2-free alternative fuel that could be used in a variety of power generations system. In this regard, solid oxide fuel cell (SOFC) technology stands out as the most promising one that directly converts ammonia into electricity with high efficiency. As SOFCs operate at high temperatures (> 600 °C), they do not require additional energy for external reforming and cracking of ammonia. In this paper, we critically review the experimental demonstration, major achievements, progress, and prospects in direct NH₃-fueled SOFCs.