Highly selective environmental electrocatalytic nitrogen reduction to ammonia on Fe2(MoO4)3/C composite electrocatalyst

Abstract

The synthesis of ammonia via electrochemical nitrogen reduction reaction (NRR) provides an attractive alternative approach to the traditional Haber-Bosch process. In this regard, a one-step hydrothermal method was adopted to synthesize a bimetallic oxide， ferric molybdate (Fe2(MoO4)3), coated with carbon black on the surface (denoted as Fe2(MoO4)3/C). The carbon black coating minimizes aggregation of Fe2(MoO4)3, leading to increased electrochemical active sites for NRR. Additionally, this coating improves the electrical conductivity of Fe2(MoO4)3 thereby accelerating electron transfer between carbon black and Fe2(MoO4)3, which is beneficial to charge transfer and enlarge the electrochemical active surface areas. At a potential of −0.4 VRHE (vs. reversible hydrogen electrode, RHE), the ammonia yield achieved was up to 51.76 μg h−1 mgcat−1, with a Faradaic efficiency of 90.63% at −0.35VRHE. Impressively, this electrocatalyst exhibited excellent cycle stability and durability.