Abstract: The promotional effects of NOx on the gas-phase oxidation of methane have been studied in the absence of solid catalysts. NOx showed an obvious catalytic activity for the partial oxidation of methane to carbon monoxide, even under strong oxidizing conditions (O2/CH4=5).The addition of 0.005％～0.2％ NO in the CH4-O2 system decreased the reaction temperatures by 200～300 ℃.Formaldehyde and ethylene were also observed in the products, and their relative concentrations were partially controlled by reaction conditions.

Key words: Methane oxidation, Catalytic effect of NO_x, Homogeneous catalysis, Catalytic combustion