A high-efficiency electrochemical proton-conducting membrane reactor for ammonia production at intermediate temperatures

Abstract

•Efficient electrochemical nitrogen reduction is successfully achieved at 350°C •The NH3 production and H2 purification processes are coupled in one reactor •The in situ supplied protons greatly accelerate the NH3 production rate Ammonia is a ubiquitous chemical raw material and hydrogen carrier with a wide range of industrial applications, which is mainly derived from the energy-intensive Haber-Bosch process. Herein, a high-efficiency ammonia synthesis technology through an excellent CO2-tolerant La5.5WO11.25 − δ (LWO) membrane reactor has been developed to improve electrocatalytic nitrogen reduction reaction performance by coupling with hydrogen purification at intermediate temperatures. From molecular hydrogen, the produced protons can be supplied in situ for ammonia synthesis by nitrogen hydrogenation. As a result, the superior ammonia synthesis performance with the highest Faradaic efficiency (FE) of 43.8% and corresponding ammonia rate of 231.1 μg h−1 cm−2 is achieved at 2,500 μA cm−2 at 350°C. This promising electrochemical membrane reactor for ammonia production at intermediate temperatures provides a feasible direction to promote the development of the ammonia synthesis industry. Ammonia is a ubiquitous chemical raw material and hydrogen carrier with a wide range of industrial applications, which is mainly derived from the energy-intensive Haber-Bosch process. Herein, a high-efficiency ammonia synthesis technology through an excellent CO2-tolerant La5.5WO11.25 − δ (LWO) membrane reactor has been developed to improve electrocatalytic nitrogen reduction reaction performance by coupling with hydrogen purification at intermediate temperatures. From molecular hydrogen, the produced protons can be supplied in situ for ammonia synthesis by nitrogen hydrogenation. As a result, the superior ammonia synthesis performance with the highest Faradaic efficiency (FE) of 43.8% and corresponding ammonia rate of 231.1 μg h−1 cm−2 is achieved at 2,500 μA cm−2 at 350°C. This promising electrochemical membrane reactor for ammonia production at intermediate temperatures provides a feasible direction to promote the development of the ammonia synthesis industry.