Initial Models of a Nonuniform Surface

The first treatment of the influence of surface nonuniformity on kinetic behavior was that of Constable [1]. He considered the surface to be composed of different sites of the i-th type, with ni representing the number of sites of type i with an activation energy of E,. The overall rate constant is then, if the preexponential factor is assumed invariant  

if a distribution function similar to that used in deriving the Freund-lich isotherm is proposed (see Chapter 5.4.1), i.e., one invoking an exponential dependence  

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