Abstract
The heterogeneous chemistry and photochemistry of chlorine nitrate adsorbed on HCl-doped crystals was studied mainly at 181 K and at 190 K. Under our experimental conditions the main gaseous products found at 181 K were Cl2O and Cl2, while at 190 K, Cl2O was mainly observed. At both temperatures a net enhancement in the rate of gaseous product formation was observed when light of wavelength longer than 350 nm entered the reactor. The obtained results in conditions where the ClONO2 concentration is higher than HCl concentration, and both are high enough to maintain saturation of the surface, showed that the rate of gaseous products formation at 181 K depends on the reactive species adsorbed while at 190 K, it is independence of them. The implications of these findings to the polar stratospheric chemistry are briefly discussed.
