Activity Enhancement of Perovskite-Type Cathode Material
A new ammonia production technology using an oxygen ion conductive solid oxide electrolyte cell (SOEC) reactor and a novel cathode material.
Ammonia is utilized in a variety of industries with 80% of produced ammonia used for fertilizer production. Most commercial ammonia is produced using the Haber-Bosch (HB) process, which requires high temperatures and pressures, resulting in high operational/production costs. The process typically uses natural gas as the feedstock for H2 production through a conversion process that releases CO2 emissions (e.g., SMR). The produced H2 is reacted with N2 using a metal catalyst (e.g., iron-based, Ru, 4% CsRu/MgO) to produce ammonia.
Alternative, more sustainable ammonia production pathways are required to address concerns and limitations with the HB processes’ high energy requirements and elevated CO2 emissions levels.
A new ammonia production technology using an oxygen ion conductive solid oxide electrolyte cell (SOEC) reactor and a novel cathode material has been developed that exhibits ionic/electronic conductivity and activity towards ammonia production from N2 and H2O. The performance of a doped lanthanum ferrite-type perovskite material is enhanced by incorporating a Fe3N-type active phase. With this cathode, the reduction of H2O is realized by the lanthanum ferrite phase, and the activation of the N2 gas phase is achieved by an iron nitride phase. The reduction of H2O produces H2 and oxide ions which are transported to the anode side through the electrolyte. The generated H2 reacts with N atoms in the iron nitride lattice forming ammonia. Testing indicated that ammonia production using a Fe3N-enhanced cathode was 2X greater than a non-Fe3N cathode.