Heptane deshydrocyclization over Pt/KL catalysts doped with barium and lanthanum

J. M. GRAU; X. L. SEOANE; A. ARCOYA

CATALYSIS LETTERS

Kluwer - Academic Plenum Publishers

Lugar: New York ; Año: 2002 vol. 83 p. 247 - 255

1011-372X

Several 1 wt% Pt/KL catalysts doped with different concentrations of either BaO or La2O3 were prepared by succesive impregnation of a zeolite KL and then characterized by H2-O2 titration, TPR, CO-FTIR, TEM-XEDS and XPS. Catalytic activity measurements in the hydroconversion of n-heptane showed that barium highly enhances the aromatization activity of Pt/KL, the more so the higher the barium concentration. The yield to aromatics increases to a lesser degree by adding 1 wt% La, but it is little modified at higher La concentrations. The CO-FTIR results suggest that the promoter effect of barium is related to an electron enrichment of Pt produced by the BaO¨Pt0 interaction which, according to the TEM-XEDS and XPS results, is more favored than the La2O3¨Pt interaction