T. Kammler et J. Kuppers, INTERACTION OF HYDROGEN-ATOMS WITH COADSORBED D CH3I ADLAYERS ON NI(100) SURFACES - EVIDENCE FOR HOT ATOM MEDIATED REACTION/, The Journal of chemical physics, 107(1), 1997, pp. 287-290
Adlayers of coadsorbed hydrogen (deuterium) atoms and methyliodide, H/
CH3I, D/CH3I, H/CD3I, D/CD3I, were prepared on Ni(100) surfaces by ads
orption of methyliodide on hydrogen (deuterium) saturated surfaces at
120 K. Upon directing thermal D (H) atoms at these adlayers as gaseous
products hydrogen and methane molecules were observed which constitut
e of surface species only, e.g., H-2 and CH4 in the combination: D-->H
/CH3I. The rates of formation of these products give evidence for reac
tion mechanisms in which adsorbed atoms, e.g., H, activated by collisi
ons with incoming atoms, e.g., D, react with surface species, either H
or CH3I to form H-2 and CH4. The reaction cross sections and isotope
effects in H-->D/CD(H)(2)I or D-->H/CH(D)(3)I reactions support a coll
ision:model in which:hot atoms act as mediators in the reaction pathwa
ys. (C) 1997 American Institute of Physics.