Catalyst stratospheric cloud

Perkas N, Koltypin Y, Palchik O, Gedanken A, Chandrasekaran S (2001) Oxidation of cyclohexane with nanostractmed amorphous catalysts imder mild conditions. Appl Catal A 209 125-130 Peter T (1997) Microphysics and heterogeneous chemistry of polar stratospheric clouds. Arm Rev Phys Chem 48 785-822... 

Johnson, J. E. and I. S. A. Isaksen (1993) Tropospheric ozone chemistry the imp)act of cloud chemistry. Journal of Atmospheric Chemistry 16, 99-122 Johnson, M. T. and T. G. Bell (2008) Concept Coupling between DMS emissions and the ocean-atmosphere exchange of ammonia. Environmental Chemistry 5, 259-267 Johnston, H. S. (1971) Reduction of stratospheric ozone by nitrogen catalysts from supersonic transport exhaust. Science 173, 517—522... 

This highly hygroscopic molecule readily combines with water molecules to form an acid aerosol droplet. Other aerosols are formed by nucleation around mineral particles injected as a result of volcanic activity. Under very cold conditions, such as at the poles in winter, these aerosols freeze to form polar stratospheric ice clouds (PSCs), the surfaces of which provide a substrate for important heterogeneous catalytic processes. An example of this is the well-known ozone hole effect. This arises because the steady state concentration of O3 is sustained by the series of reactions (5.1) and (5.21)-(5.25). As already discussed, the sink mechanism (5.24) and (5.25) requires the presence of catalyst X, of which Cl atoms are nowadays the most important, and which are provided, such as reaction (5.26), mainly by the photolysis of CFCs present at trace levels in the upper atmosphere and much of the Cl is temporarily locked up into the reservoir species such as HCl and ClOx-... 

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