CeO -supported monodispersed MoO3 clusters for high-efficiency electrochemical nitrogen reduction under ambient condition

Abstract

Abstract Developing efficient and low-cost electrocatalysts is essential for the electroreduction of N2 to NH3. Here, highly monodispersed MoO3 clusters loaded on a coral-like CeOx compound with abundant oxygen vacancies are successfully prepared by an impregnation–reduction method. The MoO3 clusters with small sizes of 2.6 ± 0.5 nm are induced and anchored by the oxygen vacancies of CeOx, resulting in excellent nitrogen reduction reaction (NRR) performance. Additionally, the synergistic effects between MoO3 and CeOx lead to a further improvement of the electrochemical performance. The as-prepared MoO3–CeOx catalyst shows an NH3 yield rate of 32.2 μg h−1 mgcat−1 and a faradaic efficiency of 7.04% at −0.75 V (vs. reversible hydrogen electrode) in 0.01 M Dulbecco's Phosphate Buffered Saline. Moreover, it displays decent electrochemical stability over 30,000 s. Besides, the electrochemical NRR mechanism for MoO3–CeOx is investigated by in-situ Fourier transform infrared spectroscopy. N–H stretching, H–N–H bending, and N–N stretching are detected during the reaction, suggesting that an associative pathway is followed. This work provides an approach to designing and synthesizing potential electrocatalysts for NRR.