Heterogeneous Reactions on Model Polar Stratospheric Cloud Surfaces: Reaction of N2O5 on Ice and Nitric Acid Trihydrate

Article abstract of DOI:10.1021/j100371a007

A Knudsen cell flow reactor was used to study the heterogeneous reaction of N2O5 on laboratory ice surfaces and nitric acid trihydrate (NAT) surfaces representative of polar stratospheric clouds (PSCs).N2O5 was quantitatively converted to HNO3 on ice surfaces at 188 K.On initially pure ice surfaces, a gradual increase in the N2O5 uptake efficiency was observed up to a maximum value near 0.03.The slow rise in reactivity with time is consistent with an acid-catalyzed surface reaction.With increasing initial nitric acid concentrations, the maximum reactivity occurred more rapidly although the overall reactivity was depressed.The uptake efficiency for N2O5 on NAT at 188 K was found to be 0.015 +/- 0.006.