Obtención de etilbenceno a partir de n-octano con catalizadores de Pt/Zeolita modificados con bario y cesio

J.M. GRAU; M.O. SOUZA; G. MARCHETTI; A. FARO; M.C. RANGEL; R. ALBURQUERQUE; M. ALVAREZ

Santa Fe, Argentina

Congreso; XIV Congreso Argentino de Catálisis; 2005

INCAPE - INTEC

Two series of Pt catalysts supported over L and Y zeolites were prepared, both in their potassium form. BaO, MgO and Cs2O were added as alkaline promoters in order to modify the properties of the metal. The concentration of the promoters was regulated to keep an atomic ratio promoter/Pt = 4. The incorporation of Pt (1% weight) is performed by incipient wetness impregnation previous to the vacuum drying of the samples and after stabilizing the promoters by calcination. The corresponding catalysts without promoters were also synthesized for comparison. The chemical composition was assessed by means of atomic absorption, the crystalline structure by XRD and the specific surface area by nitrogen adsorption. The catalysts were then evaluated in the reactions tests of dehydrocyclization of n-octane at 450 ºC, atmospheric pressure, WHSV=3,4 and molar ratio H2/n-C8=7,3. After 6 h of reaction the amount of coke on the catalyst was analyzed by means of temperature programmed oxidation. The PtZKL catalysts were more selective for the production EtBz. The addition of Ba increases the selectivity to aromatics and decreases the selectivity to isomerizationand hydrogenolysis products. The stability is strongly related to the structure of the supports. The distribution of products indicates that part of Pt is located outside the zeolite cages.