Cr₂O₃ Nanoparticle-Reduced Graphene Oxide Hybrid: A Highly Active Electrocatalyst for N₂ Reduction at Ambient Conditions

Electrochemical reduction is an eco-friendly alternative for energy-saving artificial N₂ fixation. The development of this process requires efficient N₂ reduction reaction (NRR) electrocatalysts to overcome the challenge with N₂ activation. We show that a Cr₂O₃ nanoparticle-reduced graphene oxide hybrid (Cr₂O₃-rGO) is as an outstanding catalyst for electrochemical N₂-to-NH₃ conversion under ambient conditions. In 0.1 M HCl, Cr₂O₃-rGO achieves a high NH₃ yield of 33.3 μg h^-1 mg^-1_cat. at -0.7 V vs RHE and a high Faradaic efficiency of 7.33% at -0.6 V vs RHE, with excellent selectivity for NH₃ synthesis and stability. Density functional theory calculations were executed to gain further insight into the mechanisms.