Equation and Macroscopic Rate Constants

As mentioned above, it is assumed that the system is sufficiently far from chemical equilibrium, so the reverse reactions between D and C/s/ can be neglected. In this case, the behavior of Ab/s/(E) can be described by the following kinetic scheme  

The master equation corresponding to the scheme given by Eqs. (4)-(6) and governing the time variation of the AB/s(E) surface concentration AB/s/(f, 0 has the form 

Using the principle of detailed balancing for the processes of adsorption (rate constant dkitd E)) and AB/s/( E) decomposition back to reagents (rate constant k (E)) F(E, t) can be represented in the form 

in the framework of the model under consideration, the most important effect of the bulk on the gas-surface reaction via the precursor is the relaxation of the internal energy of AB/s/. This relaxation is governed by the bulk thermal conductivity and the relaxation time trei can be estimated from 

The vibrationally excited precursor AB/s/(fs) can decay not only via energy transfer to the bulk but also via a chemical transformation (desorption of B and reaction with the formation of D and C/s/). These chemical processes can be characterized by the chemical lifetime Tch, which can be estimated in the framework of the statistical RRKM theory (see, e.g., Refs. [50, 51]) using the reaction parameters of reagents B and A/s/, precursor AB/s/, and transition complexes determined based on the results of quantum-chemical calculations. Such estimates were performed for many reactions of interest for the growth of metal oxide films [20]. It appeared that in the wide temperature range 

---