Cr2O3 nanofiber: a high-performance electrocatalyst toward artificial N2 fixation to NH3 under ambient conditions

Abstract

NH₃ synthesis heavily depends on the energy-intensive Haber–Bosch process, which produces serious carbon emission. Electrocatalytic N₂ reduction emerges as an environmentally benign process for sustainable artificial N₂ fixation but requires efficient, stable and selective catalysts for the N₂ reduction reaction (NRR). Here, we report that Cr₂O₃ nanofiber behaves as a superb non-noble-metal NRR electrocatalyst for artificial N₂ fixation to NH₃, with excellent selectivity under ambient conditions. In 0.1 M HCl, this catalyst achieves a high Faradaic efficiency of 8.56% and a high NH₃ formation rate of 28.13 μg h⁻¹ mg_cat.⁻¹, placing it amongst the most active aqueous-based NRR electrocatalysts. Moreover, this catalyst also shows strong electrochemical durability during electrolysis and the recycling test. It opens a new avenue to explore the rational design of Cr-based nanostructures as advanced catalysts for N₂ fixation and other applications.