Cr₃C₂ Nanoparticle-Embedded Carbon Nanofiber for Artificial Synthesis of NH₃ through N₂ Fixation under Ambient Conditions

Industrial production of NH 3 heavily depends on the conventional Haber–Bosch process under rigorous conditions with a large amount of energy consumption and carbon emissions. Electrocatalysis exhibits an intriguing prospect for the N 2 reduction reaction (NRR) at ambient conditions. In this case, a high-efficiency and low-cost catalyst is paramount. In this letter, Cr 3 C 2 nanoparticles and carbon nanofiber composite (Cr 3 C 2 @CNF) are proposed as a noble-metal-free NRR electrocatalyst for converting N 2 to NH 3 with an excellent selectivity. The optimal Faradic efficiency and NH 3 yield rate achieved are as high as 8.6% and 23.9 μg h –1 mg cat. –1 at −0.3 V vs reversible hydrogen electrode in 0.1 M HCl, respectively. Theoretical calculations show a low reaction barrier of merely 0.53 eV in the enzymatic route for this catalyst.