ABSTRACT
When summarizing their work on Pd (111), Engel and Ertl discussed the problem of obtaining a kinetic equation in the usual form ! = Q[ C02]/dt = f(T, £CO, £02' £ C02) describing the overall kinetics of the reaction 2CO + 02 = 2C02' Considering the fact that the ER mechanism can be excluded and only the three elementary steps (6.1), (6. 2), and (6.3) should be taken into account, the formulation of such an equation should be quite easy. This is, however, by no Ineans the case since the rate constants !s.1-!s.4 depend not only on temperature but, in a rather complicated way, also on the concentrations and mutual configurations of both reacting species which were described in the preceding section. In fact, the behavior of the surface species ordering into various LEED patterns differs very much from the ideal behavior of noninteracting chelnisorbed molecules randomly distributed at the surface assumed in the Langmuir adsorption theory.
