AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS2-TuA

Paper SS2-TuA9
Heterogeneous Reactivity of Ozone on Mineral Oxides

Tuesday, November 5, 2002, 4:40 pm, Room C-110

Session: Atmospheric Surface Chemistry
Presenter: A.E. Michel, University of Iowa
Authors: A.E. Michel, University of Iowa
C.R. Usher, University of Iowa
V.H. Grassian, University of Iowa
Correspondent: Click to Email
Mineral aerosols, or wind-blown soil particles, are emitted into the atmosphere where they can provide numerous sites for the heterogeneous reaction, physisorption and chemisorption of tropospheric gases. Understanding the role of mineral aerosol in the troposphere is important for its potential impact on chemical processes in the atmosphere. Laboratory measurements of the various processes are desired for the development of accurate atmospheric computer models. The uptake of ozone on various mineral oxide particles was observed using a Knudsen cell apparatus equipped with a quadrupole mass spectrometer. Mineral oxide samples included both commercially available powders (@alpha@-Al@sub 2@O@sub 3@, @alpha@-Fe@sub 2@O@sub 3@ and SiO@sub 2@) and authentic dusts (Saharan sand and China loess). Initial reactive uptake coefficients, @gamma@@sub BET@, were measured for the various particles and ranged from 10@super -5@ to 10@super -4@. In this investigation, it was observed that both the mineral oxide powders and authentic dusts exhibited catalytic behavior towards the destruction of ozone. Additionally, variations in the reactivity of the authentic dusts were observed as a function of sample treatment.