Boron Regulated Fe Single-Atom Structures for Electrocatalytic Nitrate Reduction to Ammonia

Electrocatalytic reduction of nitrate (NO3RR) to ammonia offers a promising approach for mitigating the environmental impact of NO3 –, while simultaneously enabling the synthesis of NH3 under ambient conditions. Recently, single-atom catalysts (SACs) have been proven to have attractive activity on NO3RR, and better catalysts with enhanced activity and stability are still in demand. Here, we report the efficient boosting of NH3 production via the NO3RR using boron-doped Fe SAC (Fe-BCN). Fe-BCN is a normal 12-hedral nanoparticle with a size of 500 nm. The NH3 Faradaic efficiency of Fe-BCN reached 97.48%, with a high ammonia production rate of 2.17 mg cm–2 h–1, in an alkaline electrolyte environment at an electrode potential of −0.3 V vs reversible hydrogen electrode. Density functional theory calculations revealed the strategy of introduced B regulating the intermediate adsorption on Fe-BCN, which enhanced the NO3RR activity. Furthermore, leveraging the high NO3RR activity of Fe-BCN, a nitrate-zinc battery with a power density of 0.90 mW cm–2 was constructed by using Fe-BCN as the cathode and zinc as the anode, respectively. This research demonstrates the broad prospects of Fe-BCN in the NO3RR and provides insights for high-performance Fe SAC electrode materials.