Plasma-catalytic synthesis of ammonia over Ru-based catalysts: Insights into the support effect
Xinbo Zhu, Jin Liu, Xueli Hu, Zijian Zhou, Xinbao Li, Weitao Wang, Renbing Wu, Xin Tu
Abstract
In this work, we have investigated the effect of different supports (activated carbon (AC), α-Al2O3, ZSM-5 and SiO2) on the plasma-catalytic synthesis of ammonia (NH3) from N2 and H2 over Ru-based catalysts in a dielectric barrier discharge (DBD) plasma reactor. Compared with the NH3 synthesis using plasma alone, the presence of the Ru-based catalysts in the DBD reactor significantly enhanced the NH3 production and energy yield by 163%–387.6% with a sequence of Ru/AC > Ru/ZSM-5 > Ru/α-Al2O3 > Ru/SiO2. The effect of different operating parameters on the plasma-catalytic NH3 synthesis over Ru/AC was also examined. N2 adsorption-desorption experiment, X-ray diffraction analysis and temperature-programmed desorption of CO2 were performed to get insights into the structure-performance relationships between the plasma-catalytic NH3 synthesis and Ru-based catalysts with different supports. Both textural properties and the basicity of the Ru/AC catalyst contributed to the enhanced NH3 production in the hybrid plasma-catalytic system.