Co4N/Co2C@rGO with Abundant Co-C and N-C Bonds as Highly Efficient Electrocatalyst for N2 Reduction

Ammonia is among the available sustainable fuels for humans in the future. Electrochemical nitrogen fixation, which is a promising ammonia synthesis method, can achieve artificial N-2 fixation at room temperature and pressure. We report that 5% Co4N/Co-2 C@rGO is a high-efficiency nitrogen reduction reaction electrocatalyst for ammonia synthesis under ambient conditions. The catalyst obtains high NH3 yield (24.12 mu g h(-1) mg(cat)(-1)) and Faradaic efficiency (24.97%) at -0.1 V (vs RHE) in 0.1 M HCl. The addition of graphene reduces CoN to Co2C and Co4N. A high ratio of Co-C bonds improves NRR performance. The excellent performance of the catalyst is attributed to the high proportion of pyridine N and pyrrole N. Data analysis results show that the NRR on the surface of Co4N adopts a favorable Mars-van Krevelen reaction mechanism. Moreover, the Co2C(101) crystal plane is more conducive to NRR.

Automated summary

This study unveiled a highly efficient electrocatalyst for ammonia synthesis under ambient conditions, achieving high NH3 yield and Faradaic efficiency in 0.1 M HCl. The catalyst's excellent performance can be attributed to the high proportion of pyridine N and pyrrole N, and the NRR mechanism on the surface of Co4N. Additionally, the Co2C(101) crystal plane enhances the NRR process.