Development of mesoporous bifunctional Pt-zeolitic catalyts for the Selective ring opening of naphthenic compunds
zeolite, USY, Pt, SRO, Naphthenes
A challenging hot topic faced by the oil refinery industry is the upgrading of low-quality distillate fractions, such as LCO, in order to meet current quality standards for diesel fuels. Thereof, an auspicious technological alternative entails the complete saturation of the aromatic structures followed by the selective cleavage of endocyclic C-C bonds in the formed naphthenic rings (selective ring opening or SRO). This work reports the influence of metal incorporation method in bifunctional Pt-USY catalysts with the aim of maximizing the dispersion at relatively high metal loadings as a means of improving their performance for the SRO of decalin as a model feed. A Pt-USY catalyst displaying low density of Brønsted acid sites and nearly monoatomic Pt dispersion (98%) at 4.9 wt% loading was prepared at optimized preparation conditions. This catalyst exhibited an outstanding performance in the SRO of decalin, giving a maximum combined yield to selective ring opening products (ROP: C10- alkylcycloalkanes + OCD: C10-alkanes) as high as 50% with a high proportion of the so-called open chain decanes (OCD) bearing the highest cetane. High (hydro) thermal stability and secondary mesoporosity of the Pt-USY catalysts make these systems highly prospective for upgrading low-quality distillate feeds.