Abstract: | The semi-empirical method of interacting bonds was used to clarify the mechanism of oscillatory behavior of the catalytic
system (NO+H2)/Rh. Various rhodium planes and surface defect regions were characterized by the strength of the nitrogen bond to the surface,
the stability of the adsorbed NHn species (n=0, 1, 2, 3), and the reactivity of NHn species towards hydrogen. Calculations admit the earlier suggested reaction mechanism, which attributes the surface wave
propagation to the intermediate formation of NHa species. The activity of the rhodium surface in oscillations is expected to increase in a row of planes: (100)<(111)<(335).
The activity of Rh(335) single crystal in the reaction rate oscillations is probably governed by the presence (in contrast
to ideal terraces) of gradient and broad range of the reaction intermediate properties.
This revised version was published online in July 2006 with corrections to the Cover Date. |