PtRe catalysts: study of the impregnation step

D.R. ARDILES, S.R. DE MIGUEL, A.A. CASTRO AND O.A. SCELZA

APPLIED CATALYSIS A-GENERAL

Elsevier

Año: 1986 vol. 24 p. 175 - 186

0926-860X

The study of the impregnation of ã-Al2O3 tablets with H2PtCl6 and HReO4 to prepare bimetallic reforming catalysts is presented. Radial concentration profiles of both metals were determined for different initial concentrations of HCl (which was used as a competitor). Moreover, a mathematical model based on a diffusion-adsorption process was used to interpret the experimental results. Parameters of the model (diffusivity and adsorption-desorption rate constants) were estimated by using the experimental measurements of the amount of solutes retained by the support as a function of the impregnation time. The reliability of calculated parameters is demonstrated by predicting radial concentration profiles under impregnation conditions different from those used for parameters estimation. In all the cases experimental and calculated profiles are in good agreement. The effect of the previous state of the support (wet or dry) on the concentration profiles was also analyzed. It can be concluded that the model can be succesfully used to predict the total amount of solutes retained by the support and the distribution profiles during the impregnation step of the preparation´ of Pt-Re/Al2O3 catalysts.