| Surface science studies have made contributions toward understanding heterogeneous catalytic processes which are essential for the chemical industry. It would be desirable to identify and model the details of surface catalytic processes at the atomic scale so as to ultimately better design more efficient catalysts. Surface science studies of catalytic processes are carried out in ultra high vacuum (UHV) and on single crystal surfaces in order to reduce complexity and to allow a focus on individual reactive steps. In this thesis, the thermal and photochemical reaction kinetics of some molecules on a single crystal Pt(111) surface will are examined. The impact of annealing on the growth of a self assembled monolayer of CH3Br and its subsequent ultraviolet photochemistry is presented. The thermal reactivity of propane on Pt(111) was investigated using a new heated effusive molecular beam technique to freeze out radical intermediate species from propane dissociative chemisorption by dosing propane at sufficiently high impinging gas temperature, Tg, for reaction to occur but sufficiently low surface temperature, Ts, that no further reactions ensued. Reflection absorption infrared spectroscopy was used to characterize the reaction intermediates. Such experimental information on reactive dissociative intermediates is important for understanding and modeling surface kinetics such as the alkane dissociative. |
