Mechanistic Implications of the GPLE Analysis

In the previous secticm it was shown that all available dispersion-time data fen sintering of model supported metal catalysts could be fitted with a secemd-ord GPLE. In a companion study it is likewise established that available dispersion-time data for sintering of conventional sui xHled metal catalysts can be fitted with either a first- or second-order GPLE.  

The ability to fit all available dispersion-time data well by either first-oider ch- second-order GPI kinetics has inqxxtantmechanistic in ilicaticms as well as practical significance. - In practical terms this new approach can be used with the well-defined database of this and the companion study to analyse the significance of important kinetic parameters k, and E (see 

Equation (4)) and their dependence on reaction conditions and catalyst prqierties. 

In principle, (he first- or second-order rate constant k provides a direct quantitative measure of sintering rate that is a functiem only of temperature, although it is shown elsewhere that rate constants should be ccxnpared fix the same order and the same approximate experimental timefi ame.  

Dgq are lower for catalysts of lower initial dispersion. Physically speaking, this is reasonable, sitx e one would expect that for a given set of ccxiditions and a fixed time, that starting with a lower dispersion, the system would end up at lower dispersion. 

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