Hydrogen production in ammonia decomposition over direct reduced iron catalyst obtained from ironmaking process

As one of the top emitters of greenhouse gases, the ironmaking industry is actively pursuing methods to reduce CO2 emissions, such as utilizing waste heat and by-products. When applying green hydrogen as a reducing agent for CO2-free ironmaking, solid direct reduced iron (DRI) with high temperatures is produced. The main component of the DRI is Fe, which makes it a potential candidate catalyst due to its high activity in ammonia decomposition. Herein, we evaluate ammonia decomposition activities and nitridation behaviors of the DRI under varying reaction conditions. The catalytic performance is enhanced at higher temperatures and lower space velocities. XRD and elemental analysis results revealed reduced peak intensities of the FexN phase and lowered nitrogen contents at elevated temperatures and lower space velocities. The catalytic properties of the DRI and its inherent thermal energy in ammonia decomposition illustrate a potential use of economical hydrogen production.