Abstract

Laser induced desorption (LID) of surface bound species is rapidly developing into an important technique for studying the dynamics of the adsorbate-substrate bond. We report here the first application of this new technique to time resolved studies of reaction kinetics on a clean metal surface. In particular, measurements of decomposition rates of methanol to form the methoxy intermediate and hydrogen are described. Surprisingly, the decomposition curves cannot be interpreted assuming a simple first order rate expression; rather, a pseudo-second order rate law is invoked to explain the data. Additional insight into the methanol decomposition reaction is obtained from studies of the reaction rate dependence on the initial concentration of methanol. Preliminary results using this technique to study the decomposition of ethylene on Ni(100) will also be discussed and compared to the methanol results.

© 1985 Optical Society of America