Physicochemical Tests on the Parameters

Testing the fit of the rate equation to the experimental data and calculating the confidence interval of the parameters should be part of any kinetic modeling study but it is not sufficient yet. With the mechanistic insight incorporated to a maximum extent into the models, the parameters of the latter should satisfy well-established physicochemical laws. As mentioned already, the rate coefficients have to obey the Arrhenius temperature dependence. Boudart et al. [1967] also derived constraints on the adsorption enthalpies and entropies which are too often overlooked. 

Since adsorption is exothermic, the adsorption enthalpy has to satisfy the inequality 

As a rule, the following limits for the adsorption entropy are observed  

An example of application of these rules to the testing of rate parameters in the dehydrogenation of methylcyclohexane on Pt and Pt/Re catalysts was published by Van Trimpont et al. [1986] and to the dehydrogenation of ethylbenzene into styrene by Won Jae Lee and Froment [2008]. 

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