AVS 57th International Symposium & Exhibition
    Surface Science Friday Sessions
       Session SS-FrM

Paper SS-FrM10
CO Photooxidation on Reduced TiO2(110) Surface

Friday, October 22, 2010, 11:20 am, Room Santa Ana

Session: Reactivity of Oxides, Mainly TiO2
Presenter: N. Petrik, Pacific Northwest National Laboratory
Authors: N. Petrik, Pacific Northwest National Laboratory
G.A. Kimmel, Pacific Northwest National Laboratory
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Photo-induced reactions between O2 and CO on reduced rutile TiO2(110) surface are studied at low temperature (~30K). Photon stimulated desorption (PSD) of O2, CO2 and CO (not reported earlier) are observed with comparable yields. Results indicate that CO2 is produced from the chemisorbed O2 molecule residing in the oxygen vacancy and CO molecule physisorbed on the Ti site next to it. The PSD angular distribution for CO2 is non-cosine, narrow and off-normal: it peaks at ~ 40 degrees to the surface normal in the (001) plane (across the Ti and O rows on the surface). The results are consistent with CO2 produced from the (Ti)-O-C-O-O-(VO) transition state complex predicted theoretically. CO PSD from the TiO2(110) surface is enhanced dramatically by the presence of chemisorbed O2 molecules, where photo-desorbing CO may be a by-product of the CO photooxidation process.