T. Biederer et al., A STRUCTURAL EFFECT IN DIRECT REACTIONS - KINETICS OF D-ABSTRACTION FROM PT(110) 1 X-2 SURFACES WITH GASEOUS H-ATOMS, Chemical physics letters, 286(1-2), 1998, pp. 15-20
Deuterium-covered Pt(110) surfaces were subjected to a flux of thermal
H atoms at 100K. The rates of product formation, HD and D-2, were mea
sured simultaneously with H atom exposure as a function of D coverage.
D-2 as a product and the kinetics of HD formation contradict the oper
ation of Eley-Rideal type mechanisms in these reactions. More appropri
ate seems the assumption that a hot-atom type mechanism operates in ab
straction of adsorbed D by gaseous H. The H/D abstraction kinetics at
Pt(110) surfaces are completely different from that observed previousl
y at Pt(111) surfaces. This structural effect puts a further question
mark on the validity of the Eley-Rideal mechanisms in abstraction reac
tions and is interpreted in the present work as a consequence of the i
nterrelation between a hot-atom mechanism and the surface structure of
the reconstructed substrate. (C) 1998 Elsevier Science B.V.