New experimental approach, based on resonant photoexcitation of gas-phase molecules in a very narrow layer boundary to the surface, was introduced recently . Localization of the photoexcitations within 80nm from a fused silica surface was achieved by utilizing the total internal reflection phenomenon responsible for the existence of an evanescent wave field within the gas media. Principal findings and the major features of the new method will be outlined while the details of the corresponding experimental studies will be presented separately as a poster . High surface chemical activity of electronically excited molecules was observed and studied at various experimental conditions indicating a general nature of the new phenomenon reported.
General model describing the mechanism of elementary chemical transformations of photoexcited molecules on a surface will be presented starting from the simple qualitative theoretical arguments which stimulated the experimental investigations. Similarities and differences of this model with the existing theoretical descriptions as well as its consistence with experimental observations obtained recently and by using the established experimental methods will be discussed.
It will be argued that experiments with electronically excited species can provide vital information for understanding of the very nature of the passways of surface chemical reactions and of the corresponding reaction dynamics effects. New possibilities to induce and control elementary chemical reactions on surface by resonant photoexcitation in gas phase will be outlined.
1. J. J. Madhukeswara and V. V. Petrunin, to be published.
2. J. J. Madhukeswara and V. V. Petrunin, Evanescent Wave Catalysis, poster at ERPS 2007.
Emneord: laser photochemistry, surface photochemistry, Surface physics
|Period||1. Sep 2007|
|Event title||Elementary Reactive Processes at Surfaces: null|
|Location||San Sebastián, Spain|
- laser photochemistry
- surface photochemistry
- Surface physics