Kinetics of catalyst deactivation

Kinetics of Catalyst Deactivation. In order to study the kinetics of the deactivation of stabilized catalyst, we carried out several sets of experiment varying pressure, with constant space velocity and with constant contact time, respectively. We assumed that reaction rate of light naphtha conversion conforms to first-order kinetics with respect to light naphtha concentration and that the decreasing rate of active site, which is caused by coke deposition, is expressed by first order. Then catalyst activity is described as exponential deactivation (S). 

J Corella, M. P. Aznar and A. Monzon, Kinetics of catalyst deactivation by nonsimple mechanism with adsorption/ desorption association at two or more active sites International Chew Engng. 29 (1969) 86 - XOO. 

Coke deactivation on Pt/Al203 catalysts have been studied intensively in the literature. Previous works have focused on the kinetics of catalyst deactivation [7] the influence of additives on coke formation [8] the coke deposition on different morphologic surfaces [9] the structure [10] and chemical composition of coke [11]. Deactivation by coke deposition on niobia supported catalysts, or even on other reducible supports which promote SMSI effect has not been studied. 

J Corella, M P. Aznar and A. Monzon, Kinetics of catalyst deactivation by... 

N.M.Ostrovskii, Kinetics of catalyst deactivation, Nauka, Moscow, 2001. 

Some approaches to the modeling of the kinetics of catalyst deactivation are also suggested by the results given in Table 3.5. We see there observations of the variations of catalyst activity with time, which in some cases are linear, exponential, or hyperbolic. Hopefully we remember from Chapter 1 that these types of temporal variations are the fingerprints of zero-, first-, and second-order reactions, respectively, so the suggestion is that catalyst deactivation kinetics may be represented by simple power-law forms. Now, how might this variation be incorporated into the rate law for a surface reaction Let us reconsider the isomerization scheme of (XXV) on an ideal surface but with the surface reaction step slow and rate-controlling ... 

---