Abstract
An approach is suggested to distinguish different types of active sites responsible for different reactions on bifunctional catalysts. The model assumes a non-uniform vulnerability of active sites that depends on their location. Problems on the relationship between the dispersion of the active phase and selectivity are discussed. The effect of coke formation on the activity change of different sites is analyzed.
An approach is suggested for modeling deactivation kinetics of multi-functional catalysts with two or three different active centers. To be consistent with Hinshelwood-Langmuir kinetics, the catalyst surface is considered as containing two/three co-existing ideal adsorbed layers that are each characterized by its intrinsic catalyst activity (ϕ(t)) and deactivation (Φ(t)) functions.