Recent progress in ammonia production via Plasma-Electrocatalysis Cascade System

Ammonia is widely utilized in agriculture to manufacture fertilizers as well as an important feedstock in the pharmaceutical, metallurgical, and textile industries. Owing to its highly compressible nature, ammonia is also regarded as an ideal carbon-free hydrogen carrier for the next-generation fuel cells. The Haber-Bosch (H-B) process is currently the main method for ammonia production but suffers from high energy consumption and intensive carbon emission. Recently, the plasma-electrochemical cascade pathway (PECP)—plasma nitrogen fixation from air in tandem with electrocatalytic synthesis of ammonia—has emerged as an alternative by the simplified process, low carbon emission, and high ammonia yield. However, the research in this area has not been summarized timely. This review systematically summarizes the research progress of PECP for the first time. Through performance and energy consumption analysis, key issues that need to be addressed have been identified: improving the efficiency of plasma nitrogen fixation and ammonia electro-synthesis. In response to these challenges, corresponding optimization strategies are provided in the end, pointing out the direction for the subsequent research on this emerging field.