Highly efficient electrochemical N 2 reduction over strongly coupled CeO 2 -Mo 2 C nanocomposites anchored by reduced graphene oxide.

Electrocatalytic N 2 fixation has been considered a most promising approach for sustainably producing NH 3 under ambient conditions. However, owing to the strong chemical inertness of N 2 , it is highly desired to explore efficient electrocatalysts for improving the yield and selectivity of nitrogen reduction. Herein, CeO 2 and Mo 2 C nanoparticles embedded simultaneously in reduced graphene oxide nanosheets (CeO 2 /Mo 2 C@rGO) are successfully fabricated for catalyzing N 2 fixation. The as-obtained CeO 2 /Mo 2 C@rGO catalyst shows superior catalytic performance with an NH 3 yield of 22.3 μg h -1 mg -1 and a faradaic efficiency (FE) of 12.7% at -0.3 V vs. the RHE, distinctly outperforming the undoped Ce counterpart of Mo 2 C@rGO. The experimental and DFT calculations reveal that the introduced Ce optimized the electronic structure, contributing to the improved NRR performance.