Efficient Conversion of NO2 into N2 and O2 in N2 or into N2O5 in Air by 172-nm Xe2 Excimer Lamp at Atmospheric Pressure

Decomposition of NO 2 (200ppm) in N 2 or air by 172-nm Xe 2 excimer lamp was studied at 1 atm. The NO 2 conversion in N 2 was 99%, and the formation ratios of N 2, O 2, NO, and N 2 O were 47, 98, 0, and 2%, respectively, after 30 min irradiation. The NO 2 in air (5-20% O 2 ) could be completely converted to N 2 O 5 and HNO 3 due to reactions by O 3 and H 2 O after only 1.0-1.5 min irradiation. The present results give a new simple photochemical aftertreatment technique of NO 2 in air without using any catalysts.