“Avaliação da tioresistência de catalisadores Pt/NaY promovidos com lantânio, praseodímio e samário na reforma do n-octano”

L.P. GOMES; M.C. RANGEL; J.L.G. FIERRO; J.M. GRAU

Gramado, Brasil

Simposio; XX Simposio Ibero Americano de Catalisis; 2006

Sociedad Brasilera de Catálisis

The effect of the addition of lanthanum, praseodymium and samarium on the thioresistance of Pt/NaY catalyst was studied in order to find efficient catalysts to produce ethylbenzene and o-xylene, high value chemicals in petrochemical industry. It was found that samarium increased the activity of platinum in the cyclohexane dehydrogenation and in the production of ethylbenzene and o-xylene, while the other promoters caused a decrease. All promoted-catalysts showed higher thioresistances as compared to Pt/NaY one, a fact which was assigned to a shift of the platinum electron density towards the electropositive centers of the promoters, weakening the platinum-sulfur bound. Samarium was the efficient promoter followed by praseodymium and samarium. This was assigned to the lanthanide contraction which decreases the effective charge in the order Sm>Pr>La and, then, samarium attracts more strongly the platinum electron density. The samariumpromoted catalyst is the most promising one, since it led to high production of ethylbenzene and o-xylene and also was the most thioresistente among the samples studied.