Engineering an electron-asymmetric Fe2O3–CeO2 nanowire array heterostructure for efficient nitrogen reduction reaction under ambient conditions

Abstract

Electrochemical N₂ reduction to NH₃ synthesis offers a green and sustainable alternative to the Haber–Bosch process. However, the extreme inertness of N₂ molecules makes the decomposition under neutral conditions extremely difficult. Therefore, it is necessary to develop a highly active and selective electrocatalyst to drive the nitrogen reduction reaction under ambient conditions to produce NH₃. Herein, we report the development of an electron-asymmetric Fe₂O₃–CeO₂ nanowire array (Fe₂O₃–CeO₂ NA) heterostructure as an efficient NRR electrocatalyst for ambient NH₃ synthesis. In 0.1 M Na₂SO₄, the Fe₂O₃–CeO₂ NA achieves a high Faradaic efficiency (12.6%) and a large NH₃ yield (36.76 µg h⁻¹ mg_cat⁻¹) at −0.3 V vs. reversible hydrogen electrode. DFT calculations indicate that the uneven distribution of charges caused by the asymmetric structure results in a high catalytic activity for the central Ce atom.