A Rare-Earth Samarium Oxide Catalyst for Electrocatalytic Nitrogen Reduction to Ammonia

A new rare-earth Sm2O3 electrocatalyst was explored for an electrochemical dinitrogen reduction reaction (NRR). Theoretical calculations reveal that the surface-exposed Sm atoms of Sm2O3 could effectively catalyze the NRR and restrict hydrogen evolution. Experimentally, we prepared Sm2O3 nanoparticles showing an NH3 yield of 27.2 μg h–1 mg–1 and a Faradaic efficiency of 11.5% at −0.6 V in 0.1 M Na2SO4, together with outstanding stability, thereby implying the potential of Sm2O3 and other rare-earth electrocatalysts for N2 electroreduction.