Decomposition of NO by Microwave Discharge of NO/He or NO/Ar Mixtures

Abstract

Abstract The decomposition of NO into N2 and O2 by a continuous or pulsed microwave discharge of NO/He or NO/Ar mixtures was studied at NO and rare-gas flow rates of 2–50 and 1000 sccm, respectively. Although discharge could be maintained in the low total-pressure range of 1–350 Torr for an NO/He mixture, stable microwave discharge could be maintained in the wide total-pressure range of 1–760 Torr for an NO/Ar mixture at a microwave power of 200 W. The decomposition efficiency of NO was measured as a function of the microwave power and of the NO flow rate in a continuous mode, and as a function of the duty cycle and the pulse period in a pulse mode. The decomposition mechanism of NO in He and Ar discharges is discussed on the basis of mass spectroscopic and emission spectroscopic data.