Abstract:

In this work, mixtures of HCHO-NO2-Ar were photolyzed under stationary conditions using a high-pressure Hg lamp atλ =300～ 340 nm and HCHO as a probe molecule. The HCO radicals were generated in the reaction system, and the kinetics of the reaction between HCO radicals and NO2 was investigated at room temperature in Ar gas at 5.7× 104 Pa pressure by FTIR spectroscopy. The main reaction products including CO, CO2, NO, HONO and H2O were detected. A small amount of N2O was found only at longer reaction times when NO2 consumption was complete. These product molecules were formed in consecutive reactions from several reaction channels. From the yields of CO and CO2,branching ratios were determined and their kinetic mechanism was discussed.

Key words: FTIR, HCO radicals, NO2, Chemical Kinetics, Elementary reactions