Ferrous-based electrolyte for simultaneous NO absorption and electroreduction to NH3 using Au/rGO electrode

Abstract

Electrochemical reduction of NO to NH3 (NORR) is an attractive approach to mildly realize NO removal and valuable NH3 production. The electrolyte, as function as the NO absorbent, is crucial to apply electrochemical technology in practical de-NO engineering. In this paper, the ferrous chelate acted as the electrolyte for effective NO absorption in NORR based on the Brown-ring reaction. The rGO and Au/rGO catalysts served as cathodes to realize ferrous regeneration for continuous NO reduction. The results revealed that ferric chelate could be fully reduced at lower onset potential on rGO electrode. The Au/rGO catalyst exhibited excellent average yield and selectivity for NH3 at − 0.1 V and pH = 6.32, (14.6 μmol* h−1 * cm−2 and 65.2%, respectively). The Faradaic Efficiency of NH3 could reach 98.3% at pH = 1.0. This work provides a valuable reference for effective NO adsorption and sustainable NO-to-NH3 conversion.