Abstract
Direct electrochemical conversion of nitric oxide (NO) into ammonia (NH3) holds great promise for high value-added utilization of industrial gaseous waste and simultaneously mitigating the human-caused imbalance of the global nitrogen cycle. Here, Fe2O3 nanorods are proposed as a superb electrocatalyst for the NO reduction reaction to produce NH3 under ambient conditions. The catalyst achieves a large NH3 yield of 78.02 mu mol h(-1) cm(-2) with a fairly high faradaic efficiency of 86.73% in neutral media. Using such a catalyst as the cathodic material, a Zn-NO battery was assembled as an NH3-producing device with excellent NO conversion efficiency, capable of delivering a power density of 1.18 mW cm(-2) and an NH3 yield of 145.28 mu g h(-1) mg(cat.)(-1). Density functional theory calculations suggest that NO binds to the Fe2O3 (104) surface most strongly via electronic state interaction, adopting a charge "acceptance-donation" mechanism and is significantly activated through the 2 pi* back-donation effect.