摘要： Emission from microwave (MW)-induced argon plasma promoted by a bed of activated coke granules was analyzed spectroscopically during non-catalytic reduction of nitric oxide (NO) at atmospheric pressure. The spectral analysis with a high resolution revealed that strong 5 peaks were recognized in a similar wavelength region to N2+ first negative band when NO molecules were included in argon plasma. The strongest peak is caused by the Ar(II) ions excited with energy corresponding to 388.033 nm in the progress of atomic transition 3s23p4(3P)4d 4D1/2 → 3s23p4(3P)4p 4D°1/2. This transition must be enhanced by an interaction with any intermediates or radical species yielded during NO reduction reactions. The plasma temperatures were determined by Boltzmann plots from intensities of any two peaks in the spectral band. The temperature was significantly different dependently on choice of two peaks, whose fact is implying non-equilibrium plasma. The maximum temperature was recognized at a high level of 40,000 K due to the activation during the reactions. The images of the plasma observed by high-speed camera showed dynamic features so that MW discharge like streamer was generated frequently in the reactor. The reaction rate could be correlated with the ratio of the area dominated by dynamic plasma to the cross section in the reactor.