Abstract

The influence of the nature of the metal precursor - platinum acetylacetonates and chloroplatinic acid - on the surface properties and catalytic activity of Pt/Al2O3 catalysts is reported. The obtained results indicate that the catalysts prepared by the organometallic route present higher metal dispersion and lower acidity compared with those prepared from H2PtCl6. On the other hand, XPS results showed that the state of platinum is essentially Pt0 in the catalysts obtained from Pt(acac)2 while in the solids prepared by impregnation of H2PtCl6 there exists an important contribution of Pt6+ species which plays a positive role in the hydrogenation of toluene. An additional hydrogen spillover due to the presence of more acidic support is also suggested as an explanation of the observed catalytic results.