Ammonia Synthesis via Electrochemical Nitrogen Reduction Reaction on Iron Molybdate under Ambient Conditions

The electrochemical nitrogen reduction reaction (NRR) is an environmentally friendly and sustainable strategy for ammonia synthesis under ambient conditions, in comparison with the traditional Haber-Bosch process. However, the N equivalent to N triple bond has a high bond energy, which causes the electrochemical NRR to suffer from sluggish kinetics. Inevitable ammonia contamination also disturbs the quantification of ammonia produced from the electrochemical NRR. To construct a bimetal-atom active center to mimic nitrogenase in nature, we herein prepared iron molybdate, Fe-2(MoO4)(3), using it as catalyst for electrochemical NRR. It is active and stable with an NH(3)yield rate of ca. 7.5 mu g h(-1)mg(cat)(-1)and a Faradaic efficiency of ca. 1.0 % in 0.1mNa(2)SO(4)at -0.7 V for 2 h, due to synergistic effect of bimetal atoms. A series of comparative experiments were subsequently conducted to reveal the origin of the activity and estimate the deviation due to ammonia contamination from the environment. Our results hold great promise for both the design of catalysts and the accurate quantification of catalytic activity for electrochemical NRR.