Heterogeneous reactions of hypochlorous acid + hydrogen chloride .fwdarw. Cl2 + H2O and chlorosyl nitrite + HCl .fwdarw. Cl2 + HNO3 on ice surfaces at polar stratospheric conditions

Abstract

Heterogeneous reactions of HOCl + HCl → Cl 2 + H 2 O (1) and ClONO 2 + HCl → Cl 2 + HNO 3 (2) on ice surfaces at a temperature of 188 K have been investigated in a flow reactor interfaced with a differentially pumped quadrupole mass spectrometer. Partial pressures for HOCl and ClONO 2 in the range of 6.5×10 -8 -2.0×10 -6 Torr, which mimic conditions in the polar stratosphere, have been used. Uptake of HCl on ice surfaces using partial pressures of HCl in the range of 1.8×10 -7 -8.0×10 -6 Torr has been measured prior to contact with HOCl or ClONO 2