In situ investigation of plasma synthesis of ammonia with porous silica catalysts

Plasma catalytic synthesis of ammonia is a promising component of electrification of manufacturing for green economy and energy storage due to the adaptability of this process to intermittent sources of electricity. Nevertheless, many problems remain in achieving both the output and the efficiency required for practical implementation. Solving these problems will require a detailed understanding of the role of plasma conditions, such as electron temperature and density as well as vibrational excitation temperatures of molecular nitrogen in the requirements for the catalyst design. Our previous experiments with mesoporous silica catalyst in a packed bed reactor showed that this catalyst produces the highest output concentrations of ammonia at high plasma density and hence high power, but at lower plasma density, the addition of a metal catalyst is beneficial to the overall concentration of ammonia. A reactor is designed that allows us to determine plasma conditions and ammonia concentration in the reactor in situ and in real time during plasma catalysis. The new reactor design will aid in the understanding of the role of plasma parameters for the appropriate design of the catalyst composition and structure.