Time resolved electron energy loss spectroscopy of surface kinetics

Recent experiments and analysis have demonstrated that time resolved electron energy loss Spectroscopy (TREELS) can be applied effectively in the study of surface kinetics and reaction mechanisms. Some general concepts pertaining to precursor mediated dissociation, alkali-promotion, and synthesis reactions on transition metal surfaces have emerged. The dissociation of N2 on Fe(111) and NO on Rh(100) is observed to occur via a highly inclined or parallel bound precursor state. The effect of K is to increase the stability of the precursor. For NO on K-promoted Rh(100), the dissociation rate constant, containing the activation energy and preexponential factor, is apparently compensated. The formation of OH from coadsorbed O and H on Rh(100) has been fully characterized, establishing the importance of islands and the large scale structure of the reactants. The synthesis of formate (HCOO) from coadsorbed O, H2O, and CO on Rh(100) is achieved when the coadsorbed reactants are in close proximity, establishing the importance of local structure.