Highly efficient electrochemical N2 reduction over strongly coupled CeO2–Mo2C nanocomposites anchored by reduced graphene oxide

Abstract

Electrocatalytic N₂ fixation has been considered a most promising approach for sustainably producing NH₃ under ambient conditions. However, owing to the strong chemical inertness of N₂, it is highly desired to explore efficient electrocatalysts for improving the yield and selectivity of nitrogen reduction. Herein, CeO₂ and Mo₂C nanoparticles embedded simultaneously in reduced graphene oxide nanosheets (CeO₂/Mo₂C@rGO) are successfully fabricated for catalyzing N₂ fixation. The as-obtained CeO₂/Mo₂C@rGO catalyst shows superior catalytic performance with an NH₃ 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 Mo₂C@rGO. The experimental and DFT calculations reveal that the introduced Ce optimized the electronic structure, contributing to the improved NRR performance.