Non-thermal plasma synergistic Ni/Al2O3 for ammonia synthesis: Configuration and optimization of a double dielectric barrier discharge reactor

The design of efficient reaction units and the use of efficient catalysts for green and non-polluting ammonia synthesis is an important and challenging issue. In this paper, we design a high-efficiency reaction device, a coaxial double dielectric barrier discharge plasma reactor, which produces a more uniform plasma discharge during operation, changes the discharge characteristics, promotes the physicochemical reactions of ammonia synthesis, improves the efficiency of ammonia production, and reduces the energy consumption. The use of transition metal Ni and its metal oxide NiO loaded on the carrier as catalysts. The catalyst was comprehensively characterized by X-ray photoelectron spectroscopy, X-ray diffraction, and scanning electron microscope. The reaction mechanism of plasma-catalyzed ammonia synthesis was studied in detail by combining discharge characteristics, optical emission spectroscopy, and catalyst characterization. The reaction conditions and discharge parameters of the dielectric barrier discharge plasma reactor were optimized, which greatly improved the energy efficiency and synthesis rate, which could reach 1002 μmol g −1  h −1 under the optimal conditions. Based on the experimental results, we analyzed how different conditions and parameters affect the reaction of ammonia synthesis.