LAUSR

Electrochemical nitrogen reduction reaction (NRR) has been considered as a promising alternative to the traditional Haber-Bosch process for the preparation of ammonia (NH3) under ambient conditions. The development of cost-effective electrocatalysts with suppressive activity for hydrogen evolution reaction is critical for improving the efficiency of NRR. Herein, oxygen containing molybdenum carbides (O-MoC) embedded in nitrogen doped carbon layers (N-doped carbon) can be easily fabricated by pyrolyzing the chelate of dopamine and molybdate. A rate of NH3 formation of 22.5 μg•h-1•mg-1cat is obtained at -0.35 V versus reversible hydrogen electrode with a high Faradaic efficiency of 25.1% in 0.1 mM HCl + 0.5 M Li2SO4. Notably, the synthesized O-MoC@NC-800 also exhibits high selectivity (no formation of hydrazine) and electrochemical stability. The moderate electron structure induced by the interaction between O-MoC and N-doped carbon shells can effectively weaken the activity of hydrogen evolution reaction and increase the Faradic efficiency of NRR. Additionally, by applying the in-situ Fourier transform infrared spectroscopy, an associative reaction pathway is proposed on O-MoC@NC-800. This work provides new insight into the rational design of carbon encapsulated metal nanoparticles as efficient catalysts for NRR at ambient conditions.