Ru-doped, oxygen-vacancy-containing CeO2 nanorods toward N2 electroreduction
Electrochemical N2 reduction in aqueous solutions at ambient conditions is extremely challenging and requires rational design of electrocatalytic centers that can effectively adsorb and activate N2. Herein we report Ru cluster-doped, oxygen vacancy-rich CeO2 (Ru/CeO2-Vo) nanorods as an efficient N2 reduction electrocatalyst. The high-density oxygen vacancies inside CeO2 are beneficial for the adsorption of N2, and the unsaturated, low-valence Ru nanoclusters provide active sites for N2 activation and subsequent electron transfer for N2 reduction. The Ru/CeO2-Vo catalyst exhibits a high ammonia production rate of 9.87 × 10-8 mmol·s-1·cm-2 and a partial current density of 32 μA·cm-2 at −0.25 V versus reversible hydrogen electrode in aqueous solutions at ambient conditions, corresponding to a Faradaic efficiency of 11.7%. Our work suggests the synergistic effect of Ru nanocluster and oxygen vacancies in CeO2 for efficient N2 fixation.