Ammonia generation in Ns pulse and Ns pulse / RF discharges over a catalytic surface

Abstract Plasma-catalytic ammonia synthesis in a ns pulse discharge and ‘hybrid’ pulse/RF plane-to-plane geometry is studied by Fourier Transform infrared absorption spectroscopy. The data are taken preheated H 2 –N mixture, with without Ni/ γ -Al O 3 or Co/ catalyst placed the section. measurement results using two different approaches. first ‘single-stage’ process, where mixture sustained continuously. In this case, yield increases slowly, over period of tens minutes. second ‘two-stage’ activated pure nitrogen, then exposed to flow, discharge. strong overshoot NH number density at reactor exit detected, factor compared single-stage process. After initial overshoot, gradually decreases ‘single stage’ value (with on), near zero off). demonstrate that plasma-catalytic controlled N atom accumulation on surface, which reacts atoms thermally dissociated generated plasma. also show significantly higher catalyst. catalyst, their subsequent reactions plasma, relatively minor importance present conditions. An additional series measurements was made sub-breakdown RF waveform overlapped train, enhance vibrational excitation nitrogen. measured added approximately 20% baseline conditions, both This effect weaker activation atoms. Additional necessary isolate possible vibrationally excited molecules plasma catalytic reactions.