Cr 2 O 3 Nanoparticle-Reduced Graphene Oxide Hybrid: A Highly Active Electrocatalyst for N 2 Reduction at Ambient Conditions.

Electrochemical reduction is an eco-friendly alternative for energy-saving artificial N ₂ fixation. The development of this process requires efficient N ₂ reduction reaction (NRR) electrocatalysts to overcome the challenge with N ₂ activation. We show that a Cr ₂ O ₃ nanoparticle-reduced graphene oxide hybrid (Cr ₂ O ₃ -rGO) is as an outstanding catalyst for electrochemical N ₂ -to-NH ₃ conversion under ambient conditions. In 0.1 M HCl, Cr ₂ O ₃ -rGO achieves a high NH ₃ 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 NH ₃ synthesis and stability. Density functional theory calculations were executed to gain further insight into the mechanisms.