The effect of single-file diffusion limitation on the rate of an irreversible first order catalytic reaction was studied both theor. and exptl. A rate equation was derived using a relation between the effective diffusion const. and the concn. of adsorbed mols. under single-file conditions which is valid on the time scale of catalytic reactions. According to this equation there is a max. in the reaction rate as a function of the reactant concn. The hydroisomerization of 2,2-dimethylbutane on platinum loaded large crystallites of H-Mordenite was used as a test reaction to verify the theor. results. The predicted behavior was indeed confirmed exptl. By measuring the rate const. of 2,2-dimethylbutane hydroisomerization on a sample for which the reaction was kinetically controlled and by comparing the activities of the two samples, the effective diffusion const. was detd. at 270 ¿C, resulting in a value of 1.3¿10-12 m2/s. A value of 6.5¿10-8 m2/s was calcd. for the self-diffusion const.
|Name||Studies in Surface Science and Catalysis|
|Conference||conference; 13th International Zeolite Conference, Montpellier, France, 8 - 13 July 2001; 2001-07-08; 2001-07-13|
|Period||8/07/01 → 13/07/01|
|Other||13th International Zeolite Conference, Montpellier, France, 8 - 13 July 2001|