Molybdenum carbide nanodots enable efficient electrocatalytic nitrogen fixation under ambient conditions

Abstract

Electrocatalytic nitrogen fixation is considered a promising approach to achieve NH₃ production. However, due to the chemical inertness of nitrogen, it is necessary to develop efficient catalysts to facilitate the process of nitrogen reduction. Here, molybdenum carbide nanodots embedded in ultrathin carbon nanosheets (Mo₂C/C) are developed to serve as a catalyst candidate for highly efficient and robust N₂ fixation through an electrocatalytic nitrogen reduction reaction (NRR). The as-synthesized Mo₂C/C nanosheets show excellent catalytic performance with a high NH₃ yield rate (11.3 µg h⁻¹ mg⁻¹ Mo₂C ) and Faradic efficiency (7.8%) for NRR under ambient conditions. More importantly, the isotopic experiments using ¹⁵N₂ as a nitrogen source confirm that the synthesized ammonia is derived from the direct supply of nitrogen. This result also demonstrates the possibility of high-efficiency nitrogen reduction even though accompanied with vigorous hydrogen evolution.