Dielectric barrier discharge-induced NH ₃ synthesis from N ₂ and H ₂ : the disclosure of plasma chemistry

Abstract The influence of plasma chemistry on the ammonia synthesis reaction was explored by employing a dielectric barrier discharge plasma in this work. When the gas temperature was below 673 K, the average electron energy increased with the gas temperature, enhancing the activation and dissociation of N 2 and H 2 , and thereby facilitating the synthesis of ammonia. When the temperature was above 673 K, a significant change occurred in the discharge mode, resulting in a sharp decline in NH 3 concentration and energy efficiency. Additionally, the thermal decomposition of ammonia was intensified with temperature. When the residence time was within the range of 0.9‒4.5 s, its increase was beneficial to NH 3 concentration and energy efficiency. When the residence time exceeded 4.5 s, the drop in gas temperature led to a decrease in average electron energy, which in turn resulted in a decline in NH 3 concentration and energy efficiency.