Nitric oxide utilization for ammonia production using solid electrolysis cell at atmospheric pressure

Abstract

Electrochemical ammonia (NH3) production, an alternative to the energy-intensive Haber process, has been extensively studied based on the basis of N2 fixation; a high-yield production is hindered by the sluggish kinetics of the N2 reduction reaction (N2RR) process originating from the strong triple bonds. Thus, several studies have primarily focused on discovering efficient catalysts for the N2RR. However, the development of a rate-limiting dissociation of N2 remains a major challenge. In this study, we propose a simple strategy to improve the electrochemical NH3 production rate by using an oxygen ionic conducting ceramic-based electrolysis cell and nitric oxide (NO), which has a lower bonding energy in comparison to N2. A maximum value of the NH3 synthesis rate of 1885 μmol cm-2 h-1 (Faradaic efficiency of 34.8%) with a negligible thermal decomposition rate of 0.16% was achieved at 650 °C under atmospheric conditions. This study demonstrated an alternative approach for NO-based electrochemical NH3 production as well as the efficient utilization of NO, which is harmful to the environment. ©