Industrial-Scale Synthesis of Green Ammonia over Lanthanum Coated Iron-Based Catalysts under Mild Conditions

Recently, there is an increasing interest in utilizing renewable energy to prepare green ammonia under milder conditions. However, existing commercial iron (Fe)-based catalysts require constant operation and harsh reaction conditions, which mismatch the fluctuation and distribution of renewable solar/wind energy. Herein, we proposed a lanthanum (La) modification strategy to improve the antifluctuation and low-temperature ammonia synthesis performance of Fe-based catalyst. Dynamics experiments and theoretical simulations indicate that the introduction of La could enhance the hydrogenation of adsorbed nitrogen atoms, thereby promoting low-temperature activity. A uniform coating of La on surface can prevent the aggregation of iron nanoparticles, thus improving their stability against fluctuations. Moreover, we used the melting technique to prepare ton-scale Fe/La catalysts, in which La was uniformly deposited on Fe particles. Finally, an industrial-scale project for the flexible production of green ammonia with an annual output of hundreds of tons was built by using as-prepared Fe/La catalysts, demonstrating its industrial application value.